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Sample records for isotopic delta18o deltad

  1. An automated technique for measuring deltaD and delta18O values of porewater by direct CO2 and H2 equilibration.

    Science.gov (United States)

    Koehler, G; Wassenaar, L I; Hendry, M J

    2000-11-15

    The stable-oxygen and -hydrogen isotopic values (deltaD, delta18O) of porewater in geologic media are commonly determined on water obtained by extraction techniques such as centrifugation, mechanical squeezing, vacuum heating and cryogenic microdistillation, and azeotropic distillation. Each of these techniques may cause isotopic fractionation as part the extraction process and each is laborious. Here we demonstrate a new approach to obtain automated, high-precision deltaD and delta18O measurements of porewater in geologic sediments by direct H2- and CO2-porewater equilibration using a modified commercial CO2-water equilibrator. This technique provides an important and cost-effective improvement over current extraction methods, because many samples can be rapidly analyzed with minimal handling, thereby reducing errors and potential for isotopic fractionation. The precision and accuracy of direct H2- and CO2-porewater equilibration is comparable to or better than current porewater extraction methods. Finally, the direct equilibration technique allows investigators to obtain high-resolution (cm scale) porewater deltaD and delta18O profiles using cores from individual boreholes, eliminating the need for costly piezometers or conventional porewater extractions.

  2. Initial isotopic geochemistry ({delta} 18 O, {delta} D) of fluids from wells of the Los Humeros, Pue., geothermal field; Geoquimica isotopica ({delta} 18 O, {delta} D) inicial de fluidos de pozos del campo geotermico de Los Humeros, Pue.

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Ramirez Montes, Miguel; Tovar Aguado, Rigoberto [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

    2010-01-15

    Isotopic data ({delta} 18 O, {delta} D) from fluids from production wells at the Los Humeros, Pue., geothermal field were analyzed to investigate the possible origin of these fluids and the dominant processes of the reservoir at its initial state. According to pre-exploitation data, it is suggested the Los Humeros reservoir fluids are made of a mixture of meteoric water of very light isotopic composition (paleo-fluids) and andesitic water. The relationship {delta} D vs {delta} 18 O from pre-exploitation data indicates the produced fluids are composed of a mixture of (at least) two fluids with distinct isotopic compositions. At the more enriched end of the mixing relationship are the isotopic compositions of the wells H-23 and H-18 (located in the southern area of the field), while the lighter fluids were found in well H-16 (originally) and then in well H-16 (repaired). It was found that the liquid phases of deep wells are more enriched in {delta} 18 O while the shallow wells present lower values, suggesting a convection process at the initial state. Based on this isotopic profile, it is considered that even the production depths of the wells H-1, H-12 and H-16 (repaired) are just about the same, but their respective isotopic compositions are quite different. The {delta} 18 O value for well H-16 (repaired) seems to be that of condensate steam, while the corresponding values for wells H-1 and H-12 fall within the value interval of the deep wells (H-23). This suggests wells H-1 and H-12 are collecting very deep fluids enriched in {delta} 18 O. These results could be useful in creating a conceptual model of the reservoir. [Spanish] Se analizaron datos isotopicos ({delta}18 O, {delta}D) de los fluidos de pozos productores del campo geotermico de Los Humeros, Pue., para investigar el posible origen de los fluidos asi como los procesos dominantes del yacimiento en su estado inicial. De acuerdo con datos previos a la explotacion, se plantea que los fluidos del yacimiento

  3. Barbados Oxygen Isotope Data (delta 18O) for the Late Pleistocene

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Coral-based delta18O time-series derived from measurements made on submerged or drowned coral reef sequence. The core samples used have been described elsewhere (cf....

  4. Nauru Island Isotope (delta 18O, delta 13C) Data for 1891 to 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Nauru coral stable isotope timeseries. (166E, 0.5S, 14m bottom depth). Coral stable isotope analyses on untreated, low-speed drilled samples. Precision is +/- 0.05...

  5. Malindi, Kenya Stable Isotope Data (delta 18O, delta 13C) for 1801-1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Malindi annual oxygen isotopic composition, 1801-1994. Notes on the data: File includes columns for Year AD, Coral d18O, and SST (degrees C). The SST data are sparse...

  6. Ras Umm Sidd Oxygen Isotope (delta 18O) Data for 1750 to 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ras Umm Sidd bimonthly coral oxygen isotope data (coral core RUS-95). Notes on the data: File (Ras Umm Sidd d18O.txt.) includes columns for Year AD (bimonthly...

  7. Palmyra Island Monthly Oxygen Isotope Data (delta 18O) for 1886-1998

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Palmyra Island Monthly Coral Oxygen Isotope Data. 112-yr, monthly-resolved coral record from Palmyra Island (5 deg 52 min N, 162 deg 8 min W). The coral was drilled...

  8. Maiana Atoll Isotope (delta 18O, delta 13C) Data for 1840 to 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Maiana bimonthly oxygen isotopic composition, 1840-1995. Notes on the data: File includes columns for Year AD (bimonthly resolution = dec/jan, feb/mar) and coral...

  9. Urvina Bay Stable Isotope (delta 18O) Data for 1600 to 1992

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A. URVCOMP.TXT Site: Urvina Bay, Galapagos Islands, 00 deg 24.52 min S, 91 deg 14.04 min W. Oxygen Isotopic time series averaged from 2 cores-UR-86 (Pavona clavus,...

  10. Clipperton Atoll Core 2B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  11. Clipperton Atoll Core 3C Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  12. Clipperton Atoll Core 4B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  13. Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

  14. The delta18O composition of Antarctic coastal current waters

    International Nuclear Information System (INIS)

    Frew, R.; Heywood, K.; Dennis, P.

    1997-01-01

    The varying proportions of 18 O to 16 O in sea water provide an oceanographic trace like salinity, but with an extra degree of freedom: salt is a tracer for the oceanic fluid, whereas the isotopic composition is a tracer specifically for the water component of that fluid. Hydrogen and oxygen isotopes are the variables most intimately related to the water component in the sea, therefore thay furnish a direct link to the water in the atmosphere and on continents and to the precipitation cycle which caused the salinity changes. The ratio of 18 O to 16 O (delta 18 O) ot waters is a powerful tracer in polar regions where sea and glacial ice processes decouple delta 18 O from salinity. Here we present observations from a significant but relatively unexplored component of the Southern Ocean current system, the Antarctic Coastal Current, and its associated Antarctic Slope Front. (author)

  15. [Variations and simulation of stable isotopes in precipitation in the Heihe River basin].

    Science.gov (United States)

    Wu, Jin-Kui; Yang, Qi-Yue; Ding, Yong-Jian; Ye, Bai-Sheng; Zhang, Ming-Quan

    2011-07-01

    To study the variations of deltaD and delta18O in precipitation, 301 samples were sampled during 2002-2004 in 6 sites in the Heihe River basin, Northwestern China. The deltaD and delta18O values ranged from 59 per thousand to -254 per thousand and 6.5 per thousand to -33.4 per thousand, respectively. This wide range indicated that stable isotopes in precipitation were controlled by different condensation mechanisms as a function of air temperature and varying sources of moisture. delta18O in precipitation had a close positive relationship with the air temperature, i. e., a clear temperature effect existed in this area. At a monthly scale, no precipitation effect existed. On the other hand, a weak precipitation effect still accrued at precipitation events scale. The spatial variation of delta18O showed that the weighted average delta18O values decreased with the increasing altitude of sampling sites at a gradient of -0. 47 per thousand/100m. A regional Meteoric Water Line, deltaD = 7.82 delta18O + 7.63, was nearly identical to the Meteoric Water Line in the Northern China. The results of backward trajectory of each precipitation day at Xishui showed that the moisture of the precipitation in cold season (October to March) mainly originated from the west while the moisture source was more complicated in warm season (April to September). The simulation of seasonal delta18O variation showed that the stable isotope composition of precipitation tended to a clear sine-wave seasonal variation.

  16. There is no temperature dependence of net biochemical fractionation of hydrogen and oxygen isotopes in tree-ring cellulose.

    Science.gov (United States)

    Roden, J S; Ehleringer, J R

    2000-01-01

    The isotopic composition of tree-ring cellulose was obtained over a two-year period from small diameter, riparian zone trees along an elevational transect in Big Cottonwood Canyon, Utah, USA to test for a possible temperature dependence of net biological fractionation during cellulose synthesis. The isotope ratios of stream water varied by only 3.6% and 0.2% in deltaD and delta18O, respectively, over an elevation change of 810m. The similarity in stream water and macroenvironment over the short (13km) transect produced nearly constant stem and leaf water deltaD and delta18O values. In addition, what few seasonal variations observed in the isotopic composition of source water and atmospheric water vapor or in leaf water evaporative enrichment were experienced equally by all sites along the elevational transect. The temperature at each site along the transect spanned a range of > or = 5 degrees C as calculated using the adiabatic lapse rate. Since the deltaD and delta18O values of stem and leaf water varied little for these trees over this elevation/temperature transect, any differences in tree-ring cellulose deltaD and delta18O values should have been associated with temperature effects on net biological fractionation. However, the slopes of the regressions of elevation versus the deltaD and delta18O values of tree-ring cellulose were not significantly different from zero indicating little or no temperature dependence of net biological fractionation. Therefore, cross-site climatic reconstruction studies using the isotope ratios of cellulose need not be concerned that temperatures during the growing season have influenced results.

  17. How yield relates to ash content, Delta 13C and Delta 18O in maize grown under different water regimes.

    Science.gov (United States)

    Cabrera-Bosquet, Llorenç; Sánchez, Ciro; Araus, José Luis

    2009-11-01

    Stable isotopes have proved a valuable phenotyping tool when breeding for yield potential and drought adaptation; however, the cost and technical skills involved in isotope analysis limit its large-scale application in breeding programmes. This is particularly so for Delta(18)O despite the potential relevance of this trait in C(4) crops. The accumulation of minerals (measured as ash content) has been proposed as an inexpensive way to evaluate drought adaptation and yield in C(3) cereals, but little is known of the usefulness of this measure in C(4) cereals such as maize (Zea mays). The present study investigates how yield relates to ash content, Delta(13)C and Delta(18)O, and evaluates the use of ash content as an alternative or complementary criterion to stable isotopes in assessing yield potential and drought resistance in maize. A set of tropical maize hybrids developed by CIMMYT were subjected to different water availabilities, in order to induce water stress during the reproductive stages under field conditions. Ash content and Delta(13)C were determined in leaves and kernels. In addition, Delta(18)O was measured in kernels. Water regime significantly affected yield, ash content and stable isotopes. The results revealed a close relationship between ash content in leaves and the traits informing about plant water status. Ash content in kernels appeared to reflect differences in sink-source balance. Genotypic variation in grain yield was mainly explained by the combination of ash content and Delta(18)O, whilst Delta(13)C did not explain a significant percentage of such variation. Ash content in leaves and kernels proved a useful alternative or complementary criterion to Delta(18)O in kernels for assessing yield performance in maize grown under drought conditions.

  18. Plan of study to determine if the isotopic ratios [delta]15 N and [delta]18 O can reveal the sources of nitrate discharged by the Mississippi River into the Gulf of Mexico

    Science.gov (United States)

    Battaglin, William A.; Kendall, Carol; Goolsby, Donald A.; Boyer, Laurie L.

    1997-01-01

    Nitrate and other nutrients discharged from the Mississippi River basin are suspected of causing a zone of depleted dissolved oxygen (hypoxic zone) in the Gulf of Mexico each summer. The hypoxic zone may have an adverse effect on aquatic life and commercial fisheries. Commercial fertilizers are the dominant source of nitrogen input to the Mississippi basin. Other nitrogen sources include animal waste, fixation of atmospheric nitrogen by legumes, precipitation, domestic and industrial effluent, and the soil. The inputs of nitrogen from most of these sources to the Mississippi basin can be estimated and the outputs in surface water can be measured. However, nitrogen from each source is affected differently by physical, chemical, and biological processes that control nitrogen cycling in terrestrial and aquatic systems. Hence, the relative contributions from the various sources of nitrogen to nitrate load in the Mississippi River are unknown because the different sources may not contribute proportionally to their inputs in the basin. It may be possible to determine the relative contributions of the major sources of nitrate in river water using the stable isotopic ratios d15N and d18O of the nitrate ion. A few researchers have used the d15N and/or d18O isotope ratios to determine sources of nitrate in ground water, headwater catchments, and small rivers, but little is known about the isotopic composition of nitrate in larger rivers. The objective of this study is to measure the isotopic composition of nitrate and suspended organic matter in the Mississippi River and its major tributaries, in discharge to the Gulf of Mexico, and in streamflow from smaller watersheds that have distinct sources of nitrogen (row crops, animal wastes, and urban effluents) or are minimally impacted by man (undeveloped). Samples from seven sites on the Mississippi River and its tributaries and from 17 sites in smaller watersheds within the Mississippi River basin will be analyzed for d15N and

  19. Water and nitrogen conditions affect the relationships of Delta13C and Delta18O to gas exchange and growth in durum wheat.

    Science.gov (United States)

    Cabrera-Bosquet, Llorenç; Molero, Gemma; Nogués, Salvador; Araus, José Luis

    2009-01-01

    Whereas the effects of water and nitrogen (N) on plant Delta(13)C have been reported previously, these factors have scarcely been studied for Delta(18)O. Here the combined effect of different water and N regimes on Delta(13)C, Delta(18)O, gas exchange, water-use efficiency (WUE), and growth of four genotypes of durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] cultured in pots was studied. Water and N supply significantly increased plant growth. However, a reduction in water supply did not lead to a significant decrease in gas exchange parameters, and consequently Delta(13)C was only slightly modified by water input. Conversely, N fertilizer significantly decreased Delta(13)C. On the other hand, water supply decreased Delta(18)O values, whereas N did not affect this parameter. Delta(18)O variation was mainly determined by the amount of transpired water throughout plant growth (T(cum)), whereas Delta(13)C variation was explained in part by a combination of leaf N and stomatal conductance (g(s)). Even though the four genotypes showed significant differences in cumulative transpiration rates and biomass, this was not translated into significant differences in Delta(18)O(s). However, genotypic differences in Delta(13)C were observed. Moreover, approximately 80% of the variation in biomass across growing conditions and genotypes was explained by a combination of both isotopes, with Delta(18)O alone accounting for approximately 50%. This illustrates the usefulness of combining Delta(18)O and Delta(13)C in order to assess differences in plant growth and total transpiration, and also to provide a time-integrated record of the photosynthetic and evaporative performance of the plant during the course of crop growth.

  20. Within-canopy and ozone fumigation effects on delta13C and Delta18O in adult beech (Fagus sylvatica) trees: relation to meteorological and gas exchange parameters.

    Science.gov (United States)

    Gessler, Arthur; Löw, Markus; Heerdt, Christian; de Beeck, Maarten Op; Schumacher, Johannes; Grams, Thorsten E E; Bahnweg, Günther; Ceulemans, Reinhart; Werner, Herbert; Matyssek, Rainer; Rennenberg, Heinz; Haberer, Kristine

    2009-11-01

    In this study, the effects of different light intensities either in direct sunlight or in the shade crown of adult beech (Fagus sylvatica L.) trees on delta13C and Delta18O were determined under ambient (1 x O3) and twice-ambient (2 x O3) atmospheric ozone concentrations during two consecutive years (2003 and 2004). We analysed the isotopic composition in leaf bulk, leaf cellulose, phloem and xylem material and related the results to (a) meteorological data (air temperature, T and relative humidity, RH), (b) leaf gas exchange measurements (stomatal conductance, g(s); transpiration rate, E; and maximum photosynthetic activity, A(max)) and (c) the outcome of a steady-state evaporative enrichment model. Delta13C was significantly lower in the shade than in the sun crown in all plant materials, whilst Delta18O was increased significantly in the shade than in the sun crown in bulk material and cellulose. Elevated ozone had no effect on delta13C, although Delta18O was influenced by ozone to varied degrees during single months. We observed significant seasonal changes for both parameters, especially in 2004, and also significant differences between the study years. Relating the findings to meteorological data and gas exchange parameters, we conclude that the differences in Delta18O between the sun and the shade crown were predominantly caused by the Péclet effect. This assumption was supported by the modelled Delta18O values for leaf cellulose. It was demonstrated that independent of RH, light-dependent reduction of stomatal conductance (and thus transpiration) and of A(max) can drive the pattern of Delta18O increase with the concomitant decrease of delta13C in the shade crown. The effect of doubling ozone levels on time-integrated stomatal conductance and transpiration as indicated by the combined analysis of Delta18O and delta13C was much lower than the influence caused by the light exposure.

  1. Variation in leaf water delta D and delta 18O values during the evapotranspiration process

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Foloni, L.L.

    1984-01-01

    A theoretical model was developed to evaluate leaf water delta D and delta 18 O variation in relation to: leaf temperature, relative humidity converted to leaf temperature and delta D and delta 18 O values of atmospheric water vapour and soil water. (M.A.C.) [pt

  2. Isotope geochemistry of fluid inclusions in Permian halite with implications for the isotopic history of ocean water and the origin of saline formation waters

    International Nuclear Information System (INIS)

    Knauth, L.P.; Beeunas, M.A.

    1986-01-01

    deltaD and delta 18 O values have been determined for fluid inclusions in 45 samples of Permian halite. The inclusions are enriched in 18 O relative to the meteoric water line but are depleted in D relative to ocean water. Inclusions with the more positive delta-values coincide with the isotopic compositions expected for evaporating sea water which follows a hooked trajectory on a deltaD-delta 18 O diagram. Inclusions with more negative delta-values may represent more highly evaporated sea water but probably reflect synsedimentary or diagenetic mixing to those of a modern evaporite pan to indicate that Permian sea water was isotopically similar to modern sea water. Connate evaporite brines can have negative delta-values because of the probable hooked isotope trajectory of evaporating sea water and/or synsedimentary mixing of evaporite brines with meteoric waters. (author)

  3. Isotopic composition of cellulose from aquatic organisms

    International Nuclear Information System (INIS)

    DeNiro, M.J.; Epstein, S.

    1981-01-01

    The stable isotopic ratios of oxygen, carbon and the non-exchangeable carbon-bound hydrogen of cellulose from marine plants and animals collected in their natural habitats and from freshwater vascular plants grown in the laboratory under controlled conditions were determined. The delta 18 O values of cellulose from all the plants and animals were 27 +- 3 parts per thousand more positive than the delta 18 O values of the waters in which the organisms grew. Temperature had little or no influence on this relationship for three species of freshwater vascular plants that were analyzed. The deltaD values of the non-exchangeable hydrogen of cellulose from different organisms that grew in the same environment differed by large amounts. This difference ranged up to 200 parts per thousand for different species of algae collected at a single site; the corresponding difference for different species of tunicates and vascular plants was 60 and 20 parts per thousand respectively. The deltaD values of cellulose nitrate from different species of freshwater vascular plants grown in water of constant temperature and isotopic composition differed by as much as 60 parts per thousand. The relationship between the deltaD values of the carbon-bound hydrogen of cellulose and the water used in its synthesis displayed a significant temperature dependence for four species of freshwater vascular plants that were analyzed. (author)

  4. Oxygen isotope ratios of the Icelandic crust

    International Nuclear Information System (INIS)

    Hattori, K.; Muehlenbachs, K.

    1982-01-01

    Oxygen isotope ratios of hydrothermally altered basalts from depth of up to approx.3 km are reported from three localities in Iceland: International Research Drilling Project (IRDP) core at Reydarfjordur, eastern Iceland (Tertiary age); drill cuttings from Reykjavik (Plio-Pleistocene age); and Halocene drill cuttings from the active Krafla central volcano. Whole rock samples from these three localities have delta 18 O values averaging +3.9 +- 1.3, +2.4 +- 1.1, and -7.7 +- 2.4%, respectively. The observed values in the deeper samples from Krafla are as low as the values for any rocks previously reported. There seems to be a slight negative gradient in delta 18 O with depth at the former two localities and a more pronounced one at Krafla. Oxygen isotope fractionations between epidote and quartz and those between calcite and fluid suggests that the basalts were altered at temperatures of 300 0 --400 0 C. Low deltaD and delta 18 O of epidote and low delta 34 S of anhydrite indicate that the altering fluids in all three areas originated as meteoric waters and have undergone varied 'oxygen shifts'. Differences in the 18 O shift of the fluids are attributed to differences in hydrothermal systems; low water/rock ratios ( 5) at Krafla. The convective hydrothermal activity, which is probably driven by silicic magma beneath the central volcanoes, has caused strong subsolidus depletion of 18 O in the rocks. The primary-magnetic delta 18 O value of the rocks in the Tertiary IRDP core was about +3.9%, which is lower than that obtained for fresh basalt from other places. Such exceptionally low delta 18 O magmas are common in Iceland and may occur as the result of oxygen isotope exchange with or assimilation of altered rocks that form a thick sequence beneath the island due to isostatic subsidence

  5. Effects of recharge and discharge on delta2H and delta18O composition and chloride concentration of high arsenic/fluoride groundwater from the Datong Basin, northern China.

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu

    2013-02-01

    To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin.

  6. delta 18O variations in snow on the Devon Island ice cap, Northwest Territories, Canada

    International Nuclear Information System (INIS)

    Koerner, R.; Russel, R.D.

    1979-01-01

    A study of delta 18 O variations of snow samples taken on traverses across the Devon Island ice cap in June 1971, 1972, and 1973 has shown a difference between the accumulation conditions on the souteast and nortwest sides of the ice cap. On the souteast side there is an increasing depletion of 18 O in the snow with increasing elevation. This pattern is attibuted to the effect of orographic uplift of air masses moving over the ice cap from the southeast, which promotes condensation and precipitation due to adiabatic cooling. On the northwest side of the ice cap there is no evidence of any further depletion of 18 O in snow, neither with increasing distance from the possible moisture source in Baffin Bay to the southeast nor with increasing elevation if the air mass comes from the northwest. In this case condensation is due to isobaric cooling so that precipitation is generally from level cloud bases. The changes inferred for the isotopic composition of the water vapour as it rises up the southeast slope are found to be consistent with its depletion through precipitation under near-equilibrium conditions. It is calculated that approximately 30% of the moisture at sea level on the southeast side of the ice cap and 8% at the top of the ice cap are of local origin. Lower temporal and aerial variability of the delta values on the southeast side of the ice cap is attributed to dominance of the Baffin Bay low on that side Effecting consistency of storm conditions there. The delta values of ice in the ablation zone on the Sverdrup Glacier show the combined effect of ice movement from the accumulation to the ablation zone and climatic change during the period of movement from cold to warm and back to cold conditions again. (auth)

  7. Hydrothermal alterations and O, H, C isotopic characterization of fluids and minerals in uraniferous massif of Saint Sylvestre (France). Extension to other French intragranitic uranium deposits

    International Nuclear Information System (INIS)

    Turpin, L.

    1984-05-01

    Petrographical, mineralogical, geochemical and stable isotope ( 18 O/ 16 O, D/H, 13 C/ 12 C) studies have been performed on the leucogranitic massif of St Sylvestre (Limousin, Massif Central francais), particularly on the different hydrothermal alterations. The oxygen isotope geochemistry of granites confirms the unicity of the different facies and their sialic origin (delta 18 O whole rocks = +11.0 +- 0.5 per mill), with a major contribution of detritic sediments rich in organic matter and poor in carbonate (delta 13 C magm. CO 2 = -10.6 per mill). Late lamprophyres have a deep-seated origin (delta 18 O = + 6 per mill). The pervasive chloritization of granitic biotites occurs during the convective circulation of a fluid of meteoric origin, at temperatures around 350-450 0 C. The chemical composition of chlorite which is buffered by that of biotite and the large 18 O-shift of fluid towards high delta values indicate that water-rock ratio was not very high. Chloritization takes place in high permeability zones. In regions where porosity is generally low, fluids are ''canalised'' in localised micro-fissured zones. Very high water/rock ratios lead to the dissolution of quartz, and the formation of the ''feldspathic episyenite'' alteration facies. The isotopic features of this fluid (delta 18 O approximately - 8 per mill, deltaD approximately - 50 per mill) indicate an elevated altitude. An isotopically similar fluid is responsible for the later ''micaceous episyenite'' alteration facies, found in fractured zones. Mixing of this fluid with a sedimentary fluid (delta 18 O approximately + 10 per mill, deltaD approximately - 30 per mill, delta 13 C approximately - 18 per mill) yielded the conditions necessary for the deposit of primary economic ore. Such fluids, sedimentary or metamorphic in origin, have been recognized in most hercynian intragranitic U and Sn-W deposits [fr

  8. On the calibration of continuous, high-precision delta18O and delta2H measurements using an off-axis integrated cavity output spectrometer.

    Science.gov (United States)

    Wang, Lixin; Caylor, Kelly K; Dragoni, Danilo

    2009-02-01

    The (18)O and (2)H of water vapor serve as powerful tracers of hydrological processes. The typical method for determining water vapor delta(18)O and delta(2)H involves cryogenic trapping and isotope ratio mass spectrometry. Even with recent technical advances, these methods cannot resolve vapor composition at high temporal resolutions. In recent years, a few groups have developed continuous laser absorption spectroscopy (LAS) approaches for measuring delta(18)O and delta(2)H which achieve accuracy levels similar to those of lab-based mass spectrometry methods. Unfortunately, most LAS systems need cryogenic cooling and constant calibration to a reference gas, and have substantial power requirements, making them unsuitable for long-term field deployment at remote field sites. A new method called Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) has been developed which requires extremely low-energy consumption and neither reference gas nor cryogenic cooling. In this report, we develop a relatively simple pumping system coupled to a dew point generator to calibrate an ICOS-based instrument (Los Gatos Research Water Vapor Isotope Analyzer (WVIA) DLT-100) under various pressures using liquid water with known isotopic signatures. Results show that the WVIA can be successfully calibrated using this customized system for different pressure settings, which ensure that this instrument can be combined with other gas-sampling systems. The precisions of this instrument and the associated calibration method can reach approximately 0.08 per thousand for delta(18)O and approximately 0.4 per thousand for delta(2)H. Compared with conventional mass spectrometry and other LAS-based methods, the OA-ICOS technique provides a promising alternative tool for continuous water vapor isotopic measurements in field deployments. Copyright 2009 John Wiley & Sons, Ltd.

  9. Oxygen and hydrogen isotope studies of plutonic granitic rocks

    International Nuclear Information System (INIS)

    Taylor, H.P. Jr.

    1978-01-01

    The primary deltaD values of the biotites and hornblendes in granitic batholiths are remarkably constant at about -50 to -85, identical to the values in regional metamorphic rocks, marine sediments and greenstones, and most weathering products in temperate climates. Therefore the primary water in these igneous rocks is probably not 'juvenile', but is ultimately derived by dehydration and/or partial melting of the lower crust or subducted lithosphere. Most granitic rocks have delta 18 O = +7.0 to +10.0, probably indicating significant involvment of high- 18 O metasedimentary or altered volcanic rocks in the melting process; such an origin is demanded for many other granodiorites and tonalites that have delta 18 O = +10 to +13. Gigantic meteoric-hydrothermal convective circulation systems were established in the epizonal portions of all batholiths, locally producing very low delta 18 O values (particularly in feldspars) during subsolidus exchange. Some granitic plutons in such environments also were emplaced as low- 18 O magmas probably formed by melting or assimilation of hydrothermally altered roof rocks. However, the water/rock ratios were typically low enough that over wide areas the only evidence for meteoric water exchange in the batholiths is given by low D/H ratios (deltaK as low as -180); for example, because of latitudinal isotopic variations in meteoric waters, as one moves north through the Cordilleran batholiths of western North America an increasingly higher proportion of the granitic rocks have deltaD values lower than -120. The lowering of deltaD values commonly corelates with re-setting of K-Ar ages. (Auth.)

  10. Estimation of lake water - groundwater interactions in meromictic mining lakes by modelling isotope signatures of lake water.

    Science.gov (United States)

    Seebach, Anne; Dietz, Severine; Lessmann, Dieter; Knoeller, Kay

    2008-03-01

    A method is presented to assess lake water-groundwater interactions by modelling isotope signatures of lake water using meteorological parameters and field data. The modelling of delta(18)O and deltaD variations offers information about the groundwater influx into a meromictic Lusatian mining lake. Therefore, a water balance model is combined with an isotope water balance model to estimate analogies between simulated and measured isotope signatures within the lake water body. The model is operated with different evaporation rates to predict delta(18)O and deltaD values in a lake that is only controlled by weather conditions with neither groundwater inflow nor outflow. Comparisons between modelled and measured isotope values show whether the lake is fed by the groundwater or not. Furthermore, our investigations show that an adaptation of the Craig and Gordon model [H. Craig, L.I. Gordon. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperature, Spoleto, E. Tongiorgi (Ed.), pp. 9-130, Consiglio Nazionale delle Ricerche, Laboratorio di Geologia Nucleare, Pisa (1965).] to specific conditions in temperate regions seems necessary.

  11. A dynamic soil chamber system coupled with a tunable diode laser for online measurements of delta-13C, delta-18O, and efflux rate of soil respired CO2

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Heath H [Los Alamos National Laboratory; Mcdowell, Nate [Los Alamos National Laboratory; Hanson, David [UNM; Hunt, John [LANDCARE RESEARCH

    2009-01-01

    High frequency observations of the stable isotopic composition of CO(2) effluxes from soil have been sparse due in part to measurement challenges. We have developed an open-system method that utilizes a flow-through chamber coupled to a tunable diode laser (TDL) to quantify the rate of soil CO(2) efflux and its delta(13)C and delta(18)O values (delta(13)C(R) and delta(18)O(R), respectively). We tested the method first in the laboratory using an artificial soil test column and then in a semi-arid woodland. We found that the CO(2) efflux rates of 1.2 to 7.3 micromol m(-2) s(-1) measured by the chamber-TDL system were similar to measurements made using the chamber and an infrared gas analyzer (IRGA) (R(2) = 0.99) and compared well with efflux rates generated from the soil test column (R(2) = 0.94). Measured delta(13)C and delta(18)O values of CO(2) efflux using the chamber-TDL system at 2 min intervals were not significantly different from source air values across all efflux rates after accounting for diffusive enrichment. Field measurements during drought demonstrated a strong dependency of CO(2) efflux and isotopic composition on soil water content. Addition of water to the soil beneath the chamber resulted in average changes of +6.9 micromol m(-2) s(-1), -5.0 per thousand, and -55.0 per thousand for soil CO(2) efflux, delta(13)C(R) and delta(18)O(R), respectively. All three variables initiated responses within 2 min of water addition, with peak responses observed within 10 min for isotopes and 20 min for efflux. The observed delta(18)O(R) was more enriched than predicted from temperature-dependent H(2)O-CO(2) equilibration theory, similar to other recent observations of delta(18)O(R) from dry soils (Wingate L, Seibt U, Maseyk K, Ogee J, Almeida P, Yakir D, Pereira JS, Mencuccini M. Global Change Biol. 2008; 14: 2178). The soil chamber coupled with the TDL was found to be an effective method for capturing soil CO(2) efflux and its stable isotope composition at high

  12. Isotope geochemistry of water in Gulf Coast Salt Domes

    International Nuclear Information System (INIS)

    Knauth, L.P.; Kumar, M.B.; Martinez, J.D.

    1980-01-01

    Water found as active leaks and isolated pools in the Weeks Island, Jefferson Island, and Belle Isle salt mines of south Louisiana has delta 18 O values ranging from -4 to +11.5% 0 and deltaD values from -2.3 to -53% 0 . One sample from Weeks Island and one from Jefferson Island are isotopically similar to local surface waters and are clearly of meteoric origin. All other samples are too enriched in 18 O to be meteoric waters. In the Weeks Island mine the isotopic data define a linear array given by deltaD=3.0delta 18 O-40.1. Active leaks define the positive end of this array. Isolated pools are interpreted as inactive leaks with initial delta 18 O and deltaD values of +9.1 +- 0.5% 0 and -11% 0 +- 7% 0 , which have subsequently exchanged with water vapor in the mine air to produce the linear array of delta values. The water derived from active leaks in these three mines is too enriched in 18 O and too depleted in D to be connate ocean water or evaporite connate water trapped in the salt. Isotopic composition of water derived from the dehydration of gypsum is probably dissimilar to that of the active leaks. It is unlikely that the water has originated from the dehydration of gypsum. It is also unlikely that isotopic exchange with anhydrite is responsible for observed 18 O enrichments. Nonmeteroric water from the active leaks displays the type of 18 O enrichments characteristic of saline formation waters, where water exchanges isotopically with calcite and clay minerals. It is concluded that the nonmeteoric waters are formation waters which have become incorporated in the salt. From the observed 18 O enrichment it is calculated that formation waters were incorporated during diapiric rise of the salt at a depth of 3--4 km and have been trapped within the salt for 10--13 m.y. Large volumes of salt within salt domes are not naturally penetrated by meteoric groundwaters but can contain limited amounts of trapped formation water

  13. Secas Island Stable Isotope Data (delta 18O) for 1707 to 1984

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Secas Island Coral d18O, used to reconstruct seasonal and interannual variability in the Intertropical Convergence Zone. Site Location: Secas Island, Gulf of...

  14. Mahe, Seychelles Stable Isotope (delta 18O) Data for 1846 to 1995

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seychelles coral oxygen-18 time series, data are monthly values of d18O from July 1846 to February 1995 from a 3-m Porites lutea coral colony collected from Beau...

  15. Aqaba Core 18, Jordan Isotope (delta 18O, delta 13C) Data for 1788 to 1992

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Aqaba, Jordan, Marine Science Station Reef, cores C18 and C19 (29ó 26' N, 34ó 58' E) Water Depth 1m. collected 11/01/92 (upper 0-120cm), 11/01/93 (120-320cm)...

  16. Houtman Abrolhos Isotope (delta 18O, delta 13C) Data for 1795 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — DESCRIPTION: VARIABLES AND UNITS: Column #1: core depth in mm Column #2: delta C-13 vs V-PDB Column #3: delta O-18 vs V-PDB Column #4: assigned date in years A.D....

  17. Espiritu Santo, Vanuatu Stable Isotope (delta 18O, delta 13C) Data for 1806 to 1979

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Espiritu Santo Island, Vanuatu, 15S, 167E. 173 year record of d18O and d13C. Variable names: QSR Age, QSR 13C, QSR 18O, GRL Age, GRL Qtrly 13C, GRL Qtrly 18O,...

  18. Papua New Guinea Stable Isotope (delta 18O) Data for 1922 to 1991

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Samples were collected in 1991 and 1992 from massive Porites corals in Madang Lagoon (5 deg 13 minS; 145 deg 49 min E, .2M Depth) and at Duranguit Reef, Laing Island...

  19. Kiritimati Isotope (delta 13C, delta 18O, Sr/Ca) Data for 1938 to 1993

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The following is excerpted from Evans et al., J.Geophys. Res., in review, 1998 (please see this paper for references made in this readme file): Proxy climate data...

  20. Tarawa Stable Isotope (delta 18O, delta 13C) and Mineralogy Data for 1959 to 1979

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Tarawa Atoll, Republic of Kiribati (1 deg N, 172 deg E). Water depth: 2-4m. Coral species Hydnophora microconos. Time span: 1959-79 at monthly resolution....

  1. Using delta15N- and delta18O-values to identify nitrate sources in karst ground water, Guiyang, southwest China.

    Science.gov (United States)

    Liu, Cong-Qiang; Li, Si-Liang; Lang, Yun-Chao; Xiao, Hua-Yun

    2006-11-15

    Nitrate pollution of the karstic groundwater is an increasingly serious problem with the development of Guiyang, the capital city of Guizhou Province, southwest China. The higher content of NO3- in groundwater compared to surface water during both summer and winter seasons indicates that the karstic groundwater system cannot easily recover once contaminated with nitrate. In order to assess the sources and conversion of nitrate in the groundwater of Guiyang, we analyzed the major ions, delta(15)N-NH4+, delta(15)N-NO3-, and delta(18)O-NO3- in surface and groundwater samples collected during both summer and winter seasons. The results show that nitrate is the major dominant species of nitrogen in most water samples and there is a big variation of nitrate sources in groundwater between winter and summer season, due to fast response of groundwater to rain or surface water in the karst area. Combined with information on NO3- /Cl-, the variations of the isotope values of nitrate in the groundwater show a mixing process of multiple sources of nitrate, especially in the summer season. Chemical fertilizer and nitrification of nitrogen-containing organic materials contribute nitrate to suburban groundwater, while the sewage effluents and denitrification mainly control the nitrate distribution in urban groundwater.

  2. Daily variations of delta 18O and delta D in daily samplings of air water vapour and rain water in the Amazon Basin

    International Nuclear Information System (INIS)

    Matsui, E.; Salati, E.; Ribeiro, M.N.G.; Tancredi, A.C.F.N.S.; Reis, C.M. dos

    1984-01-01

    The movement of rain water in the soil from 0 to 120 cm depth using delta 18 O weekly variations is studied. A study of the delta D variability in water vapour and rain water samples during precipitation was also done, the samples being collected a 3 minute intervals from the beginning to the end of precipitation. (M.A.C.) [pt

  3. Estimation of water transit time in soils under Amazon forest cover using variations in delta18O values

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Matsui, E.; Salati, E.

    1984-01-01

    The work was carried out at the forest reserve of the Instituto Nacional de Pesquisas da Amazonia, located at km 45 of Manaus, in an area characterized by Amazon vegetation of the 'terra-firme' type. To extract the soil water, four soil-water collecting stations were installed, and in each the porous cups were placed at 15, 25, 50, 80 and 120 cm depth from the soil surface. The rain-water and soil-water samples were collected only weekly for analysis of the 18 O content. In an attempt to estimate the soil-water transit time using the variation in 18 O values, a statistical model was used. This model is based on linear regression analysis applied to the values observed for soil water and rain water. From this analysis, regression coefficients are obtained which vary according to time. The values of the coefficients obtained can be adjusted generally, according to a quadratic regression, with the maximum value of the function representing the time in which the best statistical correlation between the observed delta 18 O values occurs. The time obtained from these correlations represents the mean time necessary for the water to run from one collecting point to the next. (author)

  4. Solar cycles in the last centuries in 10Be and delta18O in polar ice and in thermoluminescence signals of a sea sediment

    International Nuclear Information System (INIS)

    Cini Castagnoli, G.; Bonino, G.; Galli, M.; Beer, J.

    1984-01-01

    The cyclogram method of time series analysis has been used to analyse 10 Be data (1181-1800 AD) and delta 18 O data (1181-1960 AD) from an artic ice core and thermoluminescence data (1181-1960 AD) from a Mediterranean sediment core. The 10 Be concentrations were determined at the ETH Zurich. The delta 18 O values were measured at the University of Copenhagen. The TL measurements were performed at the Istituto di Cosmo-geofisica del C.N.R., Torino. Common mean periodicities of 10.75 y are found for the period 1505 to 1710 AD in TL and 10 Be and of 11.4 y for the period 1715 to 1880 in TL and delta 18 O. This periodicity was found in the solar sunspot (Rsub(z)) series analysed in the same way, from 1825 to 1905. This supports the argument that the common periodicities found in the long-running series are peculiar of the solar activity in the past

  5. Fractionation of oxygen isotopes between mammalian bone-phosphate and environmental drinking water

    International Nuclear Information System (INIS)

    Luz, B.; Kolodny, V.; Horowitz, M.

    1984-01-01

    The delta 18 O of mammalian bone-phosphate varies linearly with delta 18 O of environmental water, but is not in isotopic equilibrium with that water. This situation is explained by a model of delta 18 O in body water in which the important fluxes of exchangeable oxygen through the body are taken into account. Fractionation of oxygen isotopes between body and environmental drinking water is dependent on the rates of drinking and respiration. Isotopic fractionation can be estimated from physiological data and the estimates correlate very well with observed fractionation. Species whose water consumption is large relative to its energy expenditure is sensitive to isotopic ratio changes in environmental water. (author)

  6. A reexamination of cellulose carbon-bound hydrogen deltaD measurements and some factors affecting plant-water D/H relationships

    International Nuclear Information System (INIS)

    Yapp, C.J.; Epstein, S.

    1982-01-01

    The method of Epstein et al. (1976) for analysis of D/H ratios of cellulose carbon-bound hydrogen has been modified. This modified 'renitration' method yields deltaD values which are in agreement with those obtained by the sodium chlorite delignification method. Comparison of results obtained by the renitration method with the published results of Epstein et al. indicate some differences in the deltaD values of individual samples. However, the overall plant-water deltaD relationship determined by Epstein et al., is not greatly changed upon redetermination by the renitration method. Additional data from a variety of plants representing a wide geographical range reveal that relative humidity is an important variable in determining the deltaD value of cellulose C-H hydrogen on this inter-regional scale. The role of relative humidity can be reasonably explained by a leaf water model that assumes an isotopic steady-state during transpiration. These results reaffirm the conclusion of Epstein et al., that the deltaD variations of the source water are the dominant control of the deltaD variations of cellulose C-H hydrogen from naturally grown plants. Thus, there is an expectation that these cellulose deltaD variations can have climate significance. (author)

  7. Stable isotopic and mineralogical studies of hydrothermal alteration at Arima Spa, Southwest Japan

    International Nuclear Information System (INIS)

    Masuda, Harue; Osaka City Univ.; Sakai, Hitoshi; Chiba, Hitoshi; Matsuhisa, Yukihiro; Nakamura, Takeshi

    1986-01-01

    The waters of Arima Spa, Southwest Japan, have high salinity (Cl = 54 g/kg) and high isotopic ratios (deltaD = -32, and delta 18 O = +10 per mille), and issue from shallow wells drilled into altered rhyolitic pyroclastic rocks of Cretaceous age. Alteration of the host rocks occurred in two stages. The earlier regional alteration stage is characterized by the presence of 2M- and 1M-type muscovite, albite, chlorite, calcite and epidote, whereas muscovite and Fe-chlorite formation at the expense of partly albitized plagioclase and altered biotite or hornblende occurred in the following hydrothermal stage. Pyrite, sphalerite, galena and siderite are present in the central part of the hydrothermal alteration zone. Oxygen and hydrogen isotopic ratios of secondary muscovite show that regional alteration proceeded under the meteoric circulation, and that the hydrothermal fluid for the second stage had chemical and stable isotopic characteristics of non-meteoric origin similar to the present-day Arima brine. The oxygen and to a lesser extent the hydrogen isotopic ratios of the muscovite rapidly decrease with increasing distance from the central zone of hydrothermal alteration. The isotopic variation is best interpreted as reflecting rapidly decreasing fluid/rock ratios with increasing distance of fluid penetration from the narrow hydrothermal alteration zone into the surrounding area. The results are discussed. (author)

  8. The effect of natural weathering on the chemical and isotopic composition of biotites

    International Nuclear Information System (INIS)

    Clauer, N.; Bonnot-Courtois, C.

    1982-01-01

    The effect of progressive natural weathering on the isotopic (Rb-Sr, K-Ar, deltaD, delta 18 O) and chemical (REE, H 2 O + ) compositions of biotite has been studied on a suite of migmatitic biotites from the Chad Republic. During the early stages of weathering the Rb-Sr system is strongly affected, the hydrogen and oxygen isotope compositions change markedly, the minerals are depleted in light REE, the water content increases by a factor of two, and the K-Ar system is relatively little disturbed. During intensive weathering the K-Ar system is more strongly disturbed than the Rb-Sr system. Most of the isotopic and chemical modifications take place under nonequilibrium conditions and occur before newly formed kaolinite and/or smectite can be detected. These observations suggest that (a) 'protominerals' may form within the biotite structure during the initial period of weathering, and (b) only when chemical equilibrium is approached in the weathering profile are new minerals able to form. (author)

  9. [Moisture sources of Guangzhou during the freezing disaster period in 2008 indicated by the stable isotopes of precipitation].

    Science.gov (United States)

    Liao, Cong-Yun; Zhong, Wei; Ma, Qiao-Hong; Xue, Ji-Bin; Yin, Huan-Ling; Long, Kun

    2012-04-01

    From April 2007 to June 2008, stable isotope samples of all single precipitations were collected at the intervals of 5-30 min. We choose five single precipitations in Guangzhou city that happened during the freezing disaster event (from Jan. 10 to Feb. 2, 2008) in South China, aiming to investigate the variation of stable isotopes under the extremely climatic conditions and its controlling factors. The results show that the values of deltaD and delta18O in precipitations drop significantly during this freezing disaster. The analyses of the d-excess and LMWL indicate the abnormal oceanic moisture sources. Air mass trajectory tracking shows the moisture sources were characterized by the mixture of inland and marine water vapors during the freezing disaster peak period, while the long-distance oceanic moisture sources is the dominate one. Changes of stable isotope in single rain event during the freezing disaster shows three different trends, i. e, Up trend, V-shaped trend and W-shaped trend, which may be resulted from the re-evaporation, re-condensation and the related precipitation types in association with the different vapor sources and precipitation conditions.

  10. Oxygen and Hydrogen Stable Isotope Composition of Eocene ( ~45 million year old) Fossil Tree Cellulose

    Science.gov (United States)

    Jahren, H.

    2001-05-01

    I report on \\delta18O and \\deltaD values gained from unusually old tree fossils, collected on Axel Heiberg Island of the Canadian High Arctic. A variety of workers have measured the δ ^{18}O value of cellulose and the δ D value of cellulose nitrate isolated from modern trees and compared it to various environmental parameters (esp. Epstein et al., 1977: 14 tree species sampled at 16 sites ranging from 18 \\deg to 62 \\deg North latitude; \\delta18O of cellulose ranged from +20 to +33 \\permil; \\deltaD of cellulose nitrate ranged from -181 to +18). To date the paleoenvironmental interpretations resulting from these studies have been restricted to application in recent and Quaternary earth history due to the lack of sufficiently preserved cellulose and tree ring structure in older tree fossils. An exception to this generalization are the middle Eocene (\\sim45 my old) fossil forests of Axel Heiberg Island, which contain abundant stumps, branches, twigs, cones and leaves of Metasequoia trees in exquisite preservational condition. These deciduous trees grew at a paleolatitude of 80 ° North, and endured prolonged periods of continuous daylight in the summer and continuous darkness in the winter, making the ecosystem completely unlike any forest community existing today. Fossil wood samples from the site have been slightly compressed, but otherwise exhibit minimal alteration: %C and % cellulose (by mass) are similar to modern Metasequoia wood. δ ^{18}O analyses on cellulose isolated from 14 fossil individuals has yielded the following results: range = +17 to +20 ‰ ; mean = +19 ‰ ; variability within an individual = 0.5 to 1.0 ‰ . In presentation, I will complement these results with δ D determinations on cellulose nitrate isolated from the same individuals, as well as from small plants presently growing in the arctic. I will also discuss the surprising result that Axel Heiberg fossil trees appear to have stable isotope composition as low or lower than trees

  11. Hydrogeochemical and isotopic signatures of gas hydrate-forming fluids offshore NE Sakhalin (the sea of Okhotsk): Results from the CHAOS-2003 cruises

    International Nuclear Information System (INIS)

    Mazurenko, Leonid; Matveeva, Tatiana; Soloviev, Valery; Prasolov, Eduard; Logvina, Elizaveta; Shoji, Hitoshi; Hachikubo, Akihiro; Minami, Hirotsugi; Sakagami, Hirotoshi

    2005-01-01

    During the CHAOS-2003 cruises of R/V Akademik Lavrentyev three new gas hydrate accumulations named the Chaos, the Hieroglyph and the Kitami were discovered offshore NE Sakhalin (the Sea of Okhotsk) in association with fluid venting. The main goal of this paper is to clarify the origin and the composition of gas and water involving the accumulation of vent-related gas hydrates and to reveal their mechanism of formation. Discharging of deeper sourced water is not observed based on data of the major ion distribution. Observed isotope anomalies of hydrogen (up to 2.52%) and oxygen (up to 0.36%) are higher than fractionation coefficient under gas hydrate formation (1.8% and 0.3%, respectively). These features could be explained by two processes: a) an influence of residual water during gas hydrates formation or b) involving to the process of gas hydrate formation of deep-sourced water. The latter process is most probably influence on the isotopic composition of the pore water. Studied pore water samples consist from three end members: Gas hydrate water, seawater (or in situ pore water of the basin) and deep-sourced water. Results of isotopic studies of water testify that discharged fluid is characterized by light (delta)D (up to approx. 0.11% ) and (delta) 18 O (up to approx. 0.12%). Two mechanisms of gas hydrate accumulation are distinguished: Precipitation from infiltrating gas-saturated water and segregation of pore water by diffusing gas. (Author)

  12. Huon Terrace IIa1, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  13. Laing Island, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  14. Huon Terrace VIIa3, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  15. Huon Terrace IIa3, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  16. Huon Terrace IIIb, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  17. Huon Terrace VIIa1, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  18. Huon Terrace VII1, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  19. Madang Lagoon, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  20. Huon Terrace V, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  1. Madang Terrace, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  2. Huon Terrace IIa2, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  3. Huon Terrace VII3, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  4. Laing Terrace, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  5. Huon Terrace VIIa2, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  6. Huon Peninsula, Papua New Guinea Fossil and Living Coral Isotope (delta 18O) Data for 130,000 years BP to Present

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Results of analysis of cores collected from 'fossil' massive Porites corals exposed in the raised reefs of the Huon Peninsula, Papua New Guinea (see below for age...

  7. Punta Pitt Stable Isotope and Ion Data (delta 18O, delta 13C, Cd/Ca, Mn/Ca) for 1936 to 1982.5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — File contains data presented by Shen et al. (1992a). Table includes d18O, d13C, Cd/Ca, Mn/Ca, and Ba/Ca data from a 2m coral head and, for comparison, SST records...

  8. Influence of different organic fertilizers on quality parameters and the delta(15)N, delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of orange fruit (Citrus sinensis L. Osbeck).

    Science.gov (United States)

    Rapisarda, Paolo; Camin, Federica; Fabroni, Simona; Perini, Matteo; Torrisi, Biagio; Intrigliolo, Francesco

    2010-03-24

    To investigate the influence of different types of fertilizers on quality parameters, N-containing compounds, and the delta(15)N, delta(13)C, delta(2)H, delta (34)S, and delta(18)O values of citrus fruit, a study was performed on the orange fruit cv. 'Valencia late' (Citrus sinensis L. Osbeck), which was harvested in four plots (three organic and one conventional) located on the same farm. The results demonstrated that different types of organic fertilizers containing the same amount of nitrogen did not effect important changes in orange fruit quality parameters. The levels of total N and N-containing compounds such as synephrine in fruit juice were not statistically different among the different treatments. The delta(15)N values of orange fruit grown under fertilizer derived from animal origin as well as from vegetable compost were statistically higher than those grown with mineral fertilizer. Therefore, delta(15)N values can be used as an indicator of citrus fertilization management (organic or conventional), because even when applied organic fertilizers are of different origins, the natural abundance of (15)N in organic citrus fruit remains higher than in conventional ones. These treatments also did not effect differences in the delta(13)C, delta(2)H, delta(34)S, and delta(18)O values of fruit.

  9. The dynamics of central Main Ethiopian Rift waters: Evidence from {delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr ratios

    Energy Technology Data Exchange (ETDEWEB)

    Rango, Tewodros, E-mail: tewodros.godebo@duke.edu [Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States)] [Addis Ababa University, Department of Earth Sciences, P.O. Box 1176, Addis Ababa (Ethiopia); Petrini, Riccardo; Stenni, Barbara [University of Trieste, Department of Geosciences, Via Weiss 1, I-34100 Trieste (Italy); Bianchini, Gianluca [Istituto di Geoscienze e Georisorse-CNR, Pisa (Italy)] [Department of Earth Sciences, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Slejko, Francesca [University of Trieste, Department of Geosciences, Via Weiss 1, I-34100 Trieste (Italy); Beccaluva, Luigi [Department of Earth Sciences, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Ayenew, Tenalem [Addis Ababa University, Department of Earth Sciences, P.O. Box 1176, Addis Ababa (Ethiopia)

    2010-12-15

    Research highlights: {yields} Chemical and isotope ({delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr) techniques are applied to understand various hydrological processes in the Main Ethiopian Rift. {yields} Some of the studied groundwaters display a depleted {delta}D-{delta}{sup 18}O composition when compared to the present-day average precipitation, thus suggesting that the rift floor aquifers also contains paleo-meteoric waters recharge associated with deep flow system. {yields} The pristine waters coming from the highlands display isotopic compositions characterized by less radiogenic {sup 87}Sr/{sup 86}Sr (and more depleted {delta}D, {delta}{sup 18}O). This isotopic signature subsequently evolves towards higher {sup 87}Sr/{sup 86}Sr by an interaction with the more radiogenic rhyolites of the rift and their weathered and redeposited products. - Abstract: Water samples from cold and geothermal boreholes, hot springs, lakes and rivers were analyzed for {delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr compositions in order to investigate lake water-groundwater mixing processes, water-rock interactions, and to evaluate groundwater flow paths in the central Main Ethiopian Rift (MER) of the Ziway-Shala basin. Different ranges of isotopic values were recorded for different water types: hot springs show {delta}{sup 18}O -3.36 to +3.69 and {delta}D -15.85 to +24.23, deep Aluto-Langano geothermal wells show {delta}{sup 18}O -4.65 to -1.24 and {delta}D -12.39 to -9.31, groundwater wells show {delta}{sup 18}O -3.99 to +5.14 and {delta}D -19.69 to +32.27, whereas the lakes show {delta}{sup 18}O and {delta}D in the range +3.98 to +7.92 and +26.19 to +45.71, respectively. The intersection of the Local Meteoric Water Line (LMWL: {delta}D = 7 {delta}{sup 18}O + 11.2, R{sup 2} = 0.94, n = 42) and the Local Evaporation Line (LEL: {delta}D = 5.63{delta}{sup 18}O + 8, n = 14, R{sup 2} = 0.82) was used to estimate the average isotopic composition of recharge water into the

  10. Gas and Isotope Geochemistry of 81 Steam Samples from Wells in The Geysers Geothermal Field, Sonoma and Lake Counties, California

    Science.gov (United States)

    Lowenstern, Jacob B.; Janik, Cathy J.; Fahlquist, Lynne; Johnson, Linda S.

    1999-01-01

    The Geysers geothermal field in northern California, with about 2000-MW electrical capacity, is the largest geothermal field in the world. Despite its importance as a resource and as an example of a vapor-dominated reservoir, very few complete geochemical analyses of the steam have been published (Allen and Day, 1927; Truesdell and others, 1987). This report presents data from 90 steam, gas, and condensate samples from wells in The Geysers geothermal field in northern California. Samples were collected between 1978 and 1991. Well attributes include sampling date, well name, location, total depth, and the wellhead temperature and pressure at which the sample was collected. Geochemical characteristics include the steam/gas ratio, composition of noncondensable gas (relative proportions of CO2, H2S, He, H2, O2, Ar, N2, CH4, and NH3), and isotopic values for deltaD and delta18O of H2O, delta13C of CO2, and delta34S of H2S. The compilation includes 81 analyses from 74 different production wells, 9 isotopic analyses of steam condensate pumped into injection wells, and 5 complete geochemical analyses on gases from surface fumaroles and bubbling pools. Most samples were collected as saturated steam and plot along the liquid-water/steam boiling curve. Steam-togas ratios are highest in the southeastern part of the geothermal field and lowest in the northwest, consistent with other studies. Wells in the Northwest Geysers are also enriched in N2/Ar, CO2 and CH4, deltaD, and delta18O. Well discharges from the Southeast Geysers are high in steam/gas and have isotopic compositions and N2/Ar ratios consistent with recharge by local meteoric waters. Samples from the Central Geysers show characteristics found in both the Southeast and Northwest Geysers. Gas and steam characteristics of well discharges from the Northwest Geysers are consistent with input of components from a high-temperature reservoir containing carbonrich gases derived from the host Franciscan rocks. Throughout the

  11. Behavior patterns of chemical and isotopic species (2006-2007) in the Los Azufres, Mich., geothermal field, as a response to reinjection; Patrones de comportamiento de especies quimicas e isotopicas (2006-2007) en el campo geotermico de Los Azufres, Mich., en respuesta a la reinyeccion

    Energy Technology Data Exchange (ETDEWEB)

    Barragan R, Rosa Maria; Arellano G, Victor Manuel; Martinez E, Ignacio; Aragon A, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Reyes D, Lisette; Gonzalez, Rubi [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia de Los Azufres, Morelia, Michoacan (Mexico)

    2009-07-15

    Chemical and isotopic ({delta}18 O y {delta}D) data from the Los Azufres geothermal field fluids for 2006 and 2007 were analyzed to investigate changes in their behavior patterns and their relation to reinjection. Total discharge chlorides, reservoir temperatures, excess steam in well feeding fluids, CO{sub 2} concentrations at reservoir and total discharge conditions, and liquid saturations were calculated. Contour lines of certain parameters were obtained for 2006 and 2007 to relate them to the contours obtained for 2005 and to the reinjection histories. Fluid isotopic compositions, including injection fluids, were correlated to estimate fluid mixing effects between the reservoir and reinjection fluids. Results suggest chemical parameters respond to the mass flow rate injected and to the isotopic composition of injection fluids. {delta}D vs {delta}18 O relationships show a number of wells produce different proportions of reinjection returns. In the northern zone, wells AZ-65D, AZ-13, AZ-32, AZ-9A, AZ-9AD, AZ-28A, AZ-69D and AZ-44 produce relatively high proportions, while wells AZ-5, AZ-28 and AZ-19, among others, produce lower proportions. Wells AZ-2A, AZ-16AD, AZ-46 and AZ-33 from the southern field zone produce higher proportions of reinjection returns while wells AZ-34, AZ-36 and AZ-37 produce lower proportions. The liquid saturation distribution in 2007 shows the maximum saturation zones have decreased compared with 2005 and 2006 data. In 2007, maximum liquid saturations were found around wells AZ-22 and AZ-23 (southern zone) and AZ-28, AZ-32, AZ-45 and AZ-48 (northern zone). Minimum saturations were found around wells AZ-6 and AZ-16 (southern zone) and AZ-56 (northern zone). The CO{sub 2} levels for the reservoir liquid were used to trace paths of reinjection fluids, considering these fluids are depleted in this gas. Thus the minimum CO{sub 2} contour lines indicate the movement of the reinjection fluids in the reservoir. [Spanish] Se analizaron datos

  12. Major events in Neogene oxygen isotopic records

    International Nuclear Information System (INIS)

    Kennett, J.P.; Hodell, D.A.

    1986-01-01

    Changes in oxygen isotopic ratios of foraminiferal calcite during the cainozoic have been one of the primary tools for investigating the history of Arctic and Antarctic glaciation, although interpretations of the oxygen isotopic record differ markedly. The ambiguity in interpretation results mainly from the partitioning of temperature from ice volume effects in delta 18 O changes. Oxygen isotopic records for the Cainozoic show an increase in delta 18 O values towards the present, reflecting gradual cooling and increased glaciation of the Earth's climate since the late Cretaceous. A variety of core material from the South Atlantic and South-west Pacific oceans are investigated. This composite data represents one of the most complete available with which to evaluate the evolution of glaciation during the Neogene. Expansion of ice shelves in Antarctica undoubtedly accompanied the increased glaciation of the northern hemisphere, since eustatic sea-level lowering would positively reinforce ice growth on Antarctica

  13. Stable isotope estimates of evaporation: inflow and water residence time for lakes across the United States as a tool for national lake water quality assessments

    Science.gov (United States)

    Stable isotope ratios of water (delta18O and delta2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and isotope ratios integrate information about basic hydrologic processes such as evaporation as a percentage of inflow (E/I) and ...

  14. Hydrogen and oxygen stable isotope ratios of milk in the United States.

    Science.gov (United States)

    Chesson, Lesley A; Valenzuela, Luciano O; O'Grady, Shannon P; Cerling, Thure E; Ehleringer, James R

    2010-02-24

    Models of hydrogen and oxygen incorporation in human tissues recognize the impact of geographic location on the isotopic composition of fluid intake, but inputs can include nonlocal beverages, such as milk. Milk and cow drinking water were collected from dairies, and commercially available milk was purchased from supermarkets and fast food restaurants. It was hypothesized that milk water delta(2)H and delta(18)O values record geographic location information. Correlations between milk water isotope ratios and purchase location tap water were significant. However, the amount of variation in milk delta(2)H and delta(18)O values explained by tap water was low, suggesting a single estimation of fluid input isotope ratios may not always be adequate in studies. The delta(2)H and delta(18)O values of paired milk and cow drinking water were related, suggesting potential for geographical origin assignment using stable isotope analysis. As an application example, milk water delta(18)O values were used to predict possible regions of origin for restaurant samples.

  15. Eocene to Oligocene benthic foraminiferal isotopic record in the Bay of Biscay

    International Nuclear Information System (INIS)

    Miller, K.G.; Curry, W.B.

    1982-01-01

    Oxygen and carbon isotopic records of Eocene to Oligocene benthic foraminifera from two Bay of Biscay Deep Sea Drilling Project sites are presented. The delta 18 O figures for benthic foraminifera are significantly higher than those previously reported from deeper North Atlantic sites, the differences arising it is believed from diagenetic alteration of the sediments in the deeper-buried sites. (U.K.)

  16. How the oxygen isotope ratio of rain water influences the isotope ratio of chicken eggshell carbonate

    Science.gov (United States)

    Price, Gregory; Grimes, Stephen

    2015-04-01

    The stable oxygen isotope ratio of chicken eggshell carbonate was analysed from chicken eggs laid under free range, and organic farming regimes from across the UK. The eggshell carbonate oxygen isotope data shows a clear depletion in delta18O distribution from the southwest to the northeast. Although consistently offset by around 1 permil, the same isotopic distribution as that seen in eggshell carbonate is observed in the delta18O ratio of rainfall and groundwater from across the UK. This distribution is related to the Rayleigh distillation of rainfall driven by westerly winds across the UK landmass. The clear relationship observed between eggshell delta18O values and that of rainwater presumably reflects the nature of free range chickens which must be drinking locally derived rainwater and supplementing their diet and water intake with locally derived food. These results suggest that the oxygen isotope value of chicken eggshells can be used as a forensic tool to identify the locality that free range and organic eggs were laid within the UK. Furthermore, if suitable material is preserved in the archaeological and geological record then such a relationship can potentially be used to establish the oxygen isotope value of rainwater from which ancient and / or ancestral birds lived.

  17. Measuring stable isotopes of hydrogen and oxygen in ice by means of laser spectrometry : The Bolling transition in the Dye-3 (south Greenland) ice core

    NARCIS (Netherlands)

    Trigt, R. van; Meijer, H.A.J.; Sveinbjornsdottir, A.E.; Johnsen, S.J.; Kerstel, E.R.Th.

    2002-01-01

    We report on the first application of a new technique in ice-core research, based on direct absorption infrared laser spectrometry (LS), for measuring H-2 O-17 and O-18 isotope ratios. The data are used to calculate the deuterium excess d (defined as delta(2)H - 8delta(18)O) for a section of the

  18. Oxygen isotopic composition of mammal bones as a new tool for studying ratios of paleoenvironmental water and paleoclimates

    International Nuclear Information System (INIS)

    Longinelli, A.

    1984-04-01

    The purpose of this study is to try to establish quantitative relationships between the average oxygen isotopic composition of local meteoric water, the oxygen isotopic composition of mammal body water and the oxygen isotopic composition of phosphate in mammal bones. These relationships, after calibration of the method on living specimens, would allow quantitative paleoclimatological research based on the measurement of delta 18 O(PO 4 3- ) of fossil mammal bones

  19. Conifers, angiosperm trees, and lianas: growth, whole-plant water and nitrogen use efficiency, and stable isotope composition ({delta}13C and {delta}18O) of seedlings grown in a tropical environment.

    Science.gov (United States)

    Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Turner, Benjamin L

    2008-09-01

    Seedlings of several species of gymnosperm trees, angiosperm trees, and angiosperm lianas were grown under tropical field conditions in the Republic of Panama; physiological processes controlling plant C and water fluxes were assessed across this functionally diverse range of species. Relative growth rate, r, was primarily controlled by the ratio of leaf area to plant mass, of which specific leaf area was a key component. Instantaneous photosynthesis, when expressed on a leaf-mass basis, explained 69% of variation in r (P physiological models of tropical forest trees.

  20. Oxygen and carbon isotopes of Recent calcareous nannofossils as paleoceanographic indicators

    International Nuclear Information System (INIS)

    Goodney, D.E.; Margolis, S.V.; Dudley, W.C.; Kroopnick, P.; Williams, D.F.

    1980-01-01

    Delta 18 O and delta 13 C values for several species of planktonic foraminifera and calcareous nannofossils from Recent deep-sea sediments have been studied in order to evaluate their paleoceanographic and paleotemperature potential. Nannofossils from Indian Ocean core-tops reflect isotopic temperatures as warm as, or warmer than, the temperatures reported for shallow-dwelling planktonic forminifera from the same samples. In general, deep-sea sediment samples from the world's major oceans indicate that nannofossil delta 18 O values are from 0.5 to 1 per thousand heavier than shallow-dwelling planktonic foraminifera. Although nannofossil delta 18 O values depart from thermodynamic equilibrium with oceanic surface water temperatures, the delta 18 O temperature trend parallels that of surface-dwelling planktonic foraminifera. Nannofossil delta 13 C values also depart equilibrium with surface water delta 13 C-ΣCO 2 values. A comparison of nannofossil delta 13 C data with that from planktonic foraminifera suggests that the rate of primary productivity in different water masses may be influencing the delta 13 C carbonate-secreting phytoplankton and zooplankton. (Auth.)

  1. Calibration and application of lipid hydrogen isotopic ratios for quantitative reconstruction of new england climate variability over the past 15 kyr

    Science.gov (United States)

    Hou, Juzhi

    2009-11-01

    precipitation deltaD variations, with particularly high fidelity in dry regions, although more studies in other regions will be important to further test this proxy. In Chapter 4, I present a centennial-scale record of climate change during the transition based on D/H ratios of C22 n-alkanoic acid (deltaDBA) from a sediment core in Blood Pond, Massachusetts. The abrupt climate events observed in Blood Pond records show remarkable similarity with Greenland ice core delta18O records during the Pleistocene. During the early Holocene, the northeastern North America deltaDBA record was more variable than Greenland, possibly due to the close proximity of the Laurentide ice sheet, and impact of freshwater outbursts as the ice sheet rapidly retreated. In Chapter 5, I present decadal-scale temperature records from Blood Pond, Massachusetts during the early Holocene which revealed two abrupt climate reversals. The isotopic records infer a cooling of 3˜4°C between 9.3 and 9.1 ka against the millennial scale climate background, mainly induced by changes in precipitation seasonality. In comparison, the 8.2 ka event displays smaller amplitude of temperature cooling of 1˜2°C at our southern New England site. The observed climatic reversal at ˜ 9.2 ka as representing increased proportion of winter precipitation in conjunction with a drier and cooler summer, triggered by slowdown in thermohaline circulation as a result of freshwater release from the proglacial lakes. The results suggest that the seasonality of the precipitation at the southern New England was highly sensitive to meltwater releases, especially prior to the final collapse of the LIS. In Chapter 6, I present decadal to centennial resolution temperature records from two lakes in the northeastern North America to investigate the relationship between solar activity and temperature changes during the late Pleistocene to early Holocene. The temperature reconstructions from the two lakes of 100 km apart in New England are highly

  2. Stable isotope study of ground water recharge and movement in the Shogawa Fan, Toyama

    International Nuclear Information System (INIS)

    Mizutani, Yoshihiko; Oda, Matsuhisa

    1983-01-01

    Deuterium and oxygen-18 measurements of ground and river waters of the Shogawa Fan, Toyama, have been used to identify sources of water in aquifers in the Fan. A significant difference exists in deltaD and delta 18 O values between two major rivers flowing onto the Fan. On the basis of this difference, it is indicated that aquifers in the eastern half of the Fan are recharged from the Sho River and those in the western half of the Fan are from the Oyabe River. Chloride measurements of the waters support this identification of water sources. Contributions of other water sources to the aquifers are also indicated. The flow rate of infiltration from the Sho River is estimated to be 10-13 m/day in the confined aquifers in the northern part of the Fan. (author)

  3. Isotope study in the Alpine karst region of Rawil (Switzerland)

    International Nuclear Information System (INIS)

    Schotterer, U.; Siegenthaler, U.; Oeschger, H.; Wildberger, A.; Nabholz, W.

    1978-01-01

    An isotope study in the karst of the high Alps in Switzerland is described. From 1973 to 1978 discharge, 3 H, delta 18 O, conductivity and temperature were measured in representative springs. The springs are influenced by snowmelt in late spring and summer, by rain in late summer and autumn, and in the winter period, when infiltration stops, by reservoir water. Since tritium in precipitation in the last years scattered irregularly in time and space, the residence time of winter baseflow (2-4 years) could not be determined very precisely. The pronounced difference in delta 18 O between several springs allowed us to estimate the difference in mean altitude of their recharge areas. (orig.) [de

  4. Oxygen isotopic ratio of the diatom siliceous valves: development of a new method in quantitative paleoclimatology

    International Nuclear Information System (INIS)

    Labeyrie, Laurent.

    1979-07-01

    This paper describes a new method allowing the measurement of the 18 O/ 16 O ratio of the biogenic silica oxygen, which takes into account the effects due to the organic matter and hydration water associated with this type of silica. By isotopic exchange with enriched water, we have been able to fix a treatment which eliminate all contamination and memory effects. This has permitted us to study the temperature dependance of the hydrated silica-water oxygen isotopic fractionation. As application, we present a study of the variations of the delta 18 O of fossil diatoms valves along an Equatorial Pacific sediment core covering the last 20.000 years. The results demonstrate the usefulness of the delta 18 O of the diatom silica for paleoclimatic investigations [fr

  5. Oxygen isotope fractionation between human phosphate and water revisited

    DEFF Research Database (Denmark)

    Daux, Valérie; Lécuyer, Christophe; Héran, Marie-Anne

    2008-01-01

    to investigate the impact of solid food consumption on the oxygen isotope composition of the total ingested water (drinking water+solid food water). The results, along with those from three, smaller published data sets, can be considered as random estimates of a unique delta18OW/delta18OP linear relationship...... collected at 12 sites located at latitudes ranging from 4 degrees N to 70 degrees N together with the corresponding oxygen composition of tap waters (delta18OW) from these areas. In addition, the delta18O of some raw and boiled foods were determined and simple mass balance calculations were performed......: delta18OW=1.54(+/-0.09)xdelta18OP-33.72(+/-1.51)(R2=0.87: p [H0:R2=0]=2x10(-19)). The delta18O of cooked food is higher than that of the drinking water. As a consequence, in a modern diet the delta18O of ingested water is +1.05 to 1.2 per thousand higher than that of drinking water in the area. In meat...

  6. Strontium geochemistry and carbon and oxygen isotopic compositions of Lower Proterozoic dolomite and calcite marbles from the Marmorilik Formation, West Greenland

    International Nuclear Information System (INIS)

    Garde, A.A.

    1979-01-01

    The Marmorilik Formation, Rinkian mobile belt, West Greenland, is a large, Lower Proterozoic carbonate-rock sequence, deformed and metamorphosed under greenschist to amphibolite facies conditions. The pre-deformation thickness of the sequence is at least 2000 m, with about 1400 m of dolomite marble and 350 m of calcite marble. Strontium contents of forty-two dolomite and calcite marbles range from 30 to 100 ppm and 300 to 800 ppm, respectively, whereas samples with calcite of secondary origin have strontium contents between 80 ppm and 200 ppm. Carbon and oxygen isotope ratios were determined for forty calcite and dolomite marbles as -0.2+-1.0 per 1000 delta 13 C and -9.9+-1.5 per 1000 delta 18 O (vs. PDB) and are compatible with the isotopic compositions of unmetamorphosed carbonates of similar age. Calcite from eight calciumsilicate rocks, breccias and calcite veins is significantly more negative in delta 13 C and delta 18 O. Five 13 C analyses of graphite in marble range from -9.6 to -14 per 1000. Possible post-depositional changes in the strontium content and carbon and oxygen isotope compositions are discussed. It is concluded that (a) the calcite marbles are not dedolomites and are therefore of primary origin, (b) the delta 13 C and delta 18 O values of the marbles are primary or diagenetic (i.e., pre-metamorphic), and (c) the isotopic composition of the graphite is compatible with, though not necessarily evidence for, a biogenic origin. (Auth.)

  7. Oxygen isotope variations in phosphate of biogenic apatites. Pt.1

    International Nuclear Information System (INIS)

    Kolodny, Y.; Luz, B.; Navon, O.

    1983-01-01

    The major advantage of the oxygen in phosphate isotope paleothermometry is that it is a system which records temperatures with great sensitivity while bone (and teeth) building organisms are alive, and the record is nearly perfectly preserved after death. Fish from seven water bodies of different temperatures (3-23 0 C) and different delta 18 O (values - 16 to + 3) of the water were analysed. The delta 18 O values of the analysed PO 4 vary from 6 to 25. The system passed the following tests: (a) the temperature deduced from isotopic analyses of the sequence of fish from Lake Baikal are in good agreement with the temperatures measured in the thermally stratified lake; (b) the isotopic composition of fish bone phosphate is not influenced by the isotopic composition of the phosphate which is fed to the fish, but only by temperature and water composition. Isotopic analysis of fossil fish in combination with analysis of mammal bones should be a useful tool in deciphering continental paleoclimates. (orig.)

  8. Summer precipitation influences the stable oxygen and carbon isotopic composition of tree-ring cellulose in Pinus ponderosa.

    Science.gov (United States)

    Roden, John S; Ehleringer, James R

    2007-04-01

    The carbon and oxygen isotopic composition of tree-ring cellulose was examined in ponderosa pine (Pinus ponderosa Dougl.) trees in the western USA to study seasonal patterns of precipitation inputs. Two sites (California and Oregon) had minimal summer rainfall inputs, whereas a third site (Arizona) received as much as 70% of its annual precipitation during the summer months (North American monsoon). For the Arizona site, both the delta(18)O and delta(13)C values of latewood cellulose increased as the fraction of annual precipitation occurring in the summer (July through September) increased. There were no trends in latewood cellulose delta(18)O with the absolute amount of summer rain at any site. The delta(13)C composition of latewood cellulose declined with increasing total water year precipitation for all sites. Years with below-average total precipitation tended to have a higher proportion of their annual water inputs during the summer months. Relative humidity was negatively correlated with latewood cellulose delta(13)C at all sites. Trees at the Arizona site produced latewood cellulose that was significantly more enriched in (18)O compared with trees at the Oregon or California site, implying a greater reliance on an (18)O-enriched water source. Thus, tree-ring records of cellulose delta(18)O and delta(13)C may provide useful proxy information about seasonal precipitation inputs and the variability and intensity of the North American monsoon.

  9. Insights into Wilson's Warbler migration from analyses of hydrogen stable-isotope ratios

    Science.gov (United States)

    Jeffrey F. Kelly; Viorel Atudorei; Zachary D. Sharp; Deborah M. Finch

    2002-01-01

    Our ability to link the breeding locations of individual passerines to migration stopover sites and wintering locations is limited. Stable isotopes of hydrogen contained in bird feathers have recently shown potential in this regard. We measured hydrogen stable-isotope ratios (deltaD) of feathers from breeding, migrating, and wintering Wilson's Warblers. Analyses...

  10. Isotopic measurements of carbon and oxygen in carbonates from Bambui Group in the center-north region of Bahia State

    International Nuclear Information System (INIS)

    Torquato, J.R.; Misi, A.

    1978-01-01

    Analyses of 85 carbonate samples of the Bambui Group from the Chapada de Irece, Bahia, exhibit four distinct 13 C and 18 O isotopic ratio groupings. Based on these results the following sedimentation model for the Bambui Group is proposed: 1. A continental environment originating the basal dolomitic limestones and argillacceous dolomites. Isotopic ratios from these rocks fall within ranges considered typical of continental sedimentation: delta 18 C between -2.9 and -6.4%o, and delta 18 O from -5.3 to -10.7%o (PDB). 2. An alternating continental and restricted marine environment resulting in the deposition of laminated dolomitic limestones with thin interbeds of muddy sediments. Delta 13 C ratios of +0.1 to -4.9%o and a mean value of -8.2+-0.3%o delta 18 O are compatible with such an environment. 3. A restricted marine environment dominated by sedimentation of the black, fetid limestones of the upper portion of the sequence. Isotopic ratios for 13 C are all over -1.8%o, up to about +7.5%o, and 18 O ratios vary from-4.9 to -10.0%o. A number of light-grey sileceous dolomites is interbered with the lowermost black limestones of this sequence. Isotopic data for these rocks show a narrow range for delta 18 C values (-0.5 to 1.0%o) and a broader variation for delta 18 O ratios (0.0 to -8.3%o). This latter may be interpreted as indicative of intense evaporation during deposition of the dolomitic facies [pt

  11. Stable carbon and hydrogen isotope analysis of methyl tert-butyl ether and tert-amyl methyl ether by purge and trap-gas chromatography-isotope ratio mass spectrometry: method evaluation and application.

    Science.gov (United States)

    Kujawinski, Dorothea M; Stephan, Manuel; Jochmann, Maik A; Krajenke, Karen; Haas, Joe; Schmidt, Torsten C

    2010-01-01

    In order to monitor the behaviour of contaminants in the aqueous environment effective enrichment techniques often have to be employed due to their low concentrations. In this work a robust and sensitive purge and trap-gas chromatography-isotope ratio mass spectrometry method for carbon and hydrogen isotope analysis of fuel oxygenates in water is presented. The method evaluation included the determination of method detection limits, accuracy and reproducibility of deltaD and delta(13)C values. Lowest concentrations at which reliable delta(13)C values could be determined were 5 microg L(-1) and 28 microg L(-1) for TAME and MTBE, respectively. Stable deltaD values for MTBE and TAME could be achieved for concentrations as low as 25 and 50 microg L(-1). Good long-term reproducibility of delta(13)C and deltaD values was obtained for all target compounds. But deltaD values varying more than 5 per thousand were observed using different thermal conversion tubes. Thus, a correction of deltaD values in the analysis of groundwater samples was necessary to guarantee comparability of the results. The applicability of this method was shown by the analysis of groundwater samples from a gasoline contaminated site. By two dimensional isotope analysis two locations within this site were identified at which anaerobic and aerobic degradation of methyl tert-butyl ether occurred.

  12. [Spatial and temporal variations of hydrological characteristic on the landscape zone scale in alpine cold region].

    Science.gov (United States)

    Yang, Yong-Gang; Hu, Jin-Fei; Xiao, Hong-Lang; Zou, Song-Bing; Yin, Zhen-Liang

    2013-10-01

    There are few studies on the hydrological characteristics on the landscape zone scale in alpine cold region at present. This paper aimed to identify the spatial and temporal variations in the origin and composition of the runoff, and to reveal the hydrological characteristics in each zone, based on the isotopic analysis of glacier, snow, frozen soil, groundwater, etc. The results showed that during the wet season, heavy precipitation and high temperature in the Mafengou River basin caused secondary evaporation which led to isotope fractionation effects. Therefore, the isotope values remained high. Temperature effects were significant. During the dry season, the temperature was low. Precipitation was in the solid state during the cold season and the evaporation was weak. Water vapor came from the evaporation of local water bodies. Therefore, less secondary evaporation and water vapor exchange occurred, leading to negative values of delta18O and deltaD. delta18O and deltaD values of precipitation and various water bodies exhibited strong seasonal variations. Precipitation exhibited altitude effects, delta18O = -0. 005 2H - 8. 951, deltaD = -0.018 5H - 34. 873. Other water bodies did not show altitude effects in the wet season and dry season, because the runoff was not only recharged by precipitation, but also influenced by the freezing and thawing process of the glacier, snow and frozen soil. The mutual transformation of precipitation, melt water, surface water and groundwater led to variations in isotopic composition. Therefore, homogenization and evaporation effect are the main control factors of isotope variations.

  13. Oxygen isotopic ratios in quartz as an indicator of provenance of dust

    International Nuclear Information System (INIS)

    Jackson, M.L.

    1977-01-01

    Quartz was isolated in the long range aerosol size range (fine silt, 1-10 μm in diameter) from atmospheric aerosols, wind-erosive soils, soil silts, shales, and Pacific pelagic sediments of the Northern and Southern Hemispheres, to trace their provenance or origin, as part of a study of dust mineral sequestering of 137 Cs and other products of nuclear fission. The oxygen isotopic ratio ( 18 O/ 16 O) was determined by mass spectrometry. The provenance has been established for this fine silt fraction which reflects the relative proportion of two classes of quartz source: (a) weathering of igneous and metamorphic rocks (high temperature origin and low 18 O/ 16 O ratio) and (b) of quartz crystallized in cherts and overgrowths (low temperature origin and high 18 O/ 16 O ratio). This quartz mixing ratio is a basic model or paradigm. Analyses of present day atmospheric aerosols and eolian-derived soils, Pacific pelagic sediments, and now-raised Phanerozoic marine sediments show that the Northern and Southern Hemispheres have separate large-scale reservoirs of the fine grain sizes that contribute to aerosol dusts. These can be identified by distinctive values of 18 O/ 16 O ratios of the quartz therein. The difference in quartz delta 18 O value in parts per thousand per ml ( 0 / 00 of about 12 +- 2 0 / 00 in Southern Hemisphere mixed detrital sediments and about 19 +- 2 0 / 00 in those of the Northern Hemisphere (for constant size, the 1-10 μm size fraction) results from the presence of a considerably larger proportion of quartz having low-temperature origin and higher delta 18 O values (chert, silica overgrowths, etc.) in the Northern Hemisphere reservoirs. The early paleoclimatic and paleogeochemical differences remain the control of the North-South Hemisphere difference in delta 18 O values in long-range aerosol sized quartz

  14. Biological fractionation of oxygen and carbon isotopes by recent benthic foraminifera

    International Nuclear Information System (INIS)

    Woodruff, F.; Douglas, R.G.

    1980-01-01

    Recent deep-sea benthic foraminifera from five East Pacific Rise box core tops have been analyzed for oxygen and carbon isotopic composition. The five equatorial stations, with water depths of between 3200 and 4600 m, yielded fourteen specific and generic taxonomic groups. Of the taxa analyzed, Uvigerina spp. most closely approaches oxygen isotopic equilibrium with ambient sea water. Pyrgo spp. was next closest to isotopic equilibrium, being on the average 0.59 per thousand depleted in 18 O relative to Uvigerina spp. Oridorsalis umbonatus also has relatively high delta 18 O values. Most other taxa were depleted in 18 O by large amounts. In no taxa was the carbon in the CaCO 3 secreted in carbon isotopic equilibrium with the dissolved HCO 3 - of ambient sea water. (Auth.)

  15. Vertical distribution and isotopic composition of living planktonic foraminifera in the western North Atlantic

    International Nuclear Information System (INIS)

    Fairbanks, R.G.; Wiebe, P.H.; Be, A.W.H.

    1980-01-01

    Thirteen species of planktonic foraminifera collected with vertically stratified zooplankton tows in the slope water, Gulf Stream cold core ring, and northern Sargasso Sea show significant differences in their vertical distributions in the upper 200 meters of these different hydrographic regimes. Gulf Stream cold core rings may be responsible for a southern displacement of the faunal boundary associated with the Gulf Stream when reconstructed from the deep-sea sediment record. Oxygen isotope analyses of seven species reveal that nonspinose species (algal symbiont-barren) apparently calcify in oxygen isotope equilibrium, whereas spinose species usually calcify out of oxygen isotope equilibrium by approximately -0.3 to -0.4 per mil in delta 18 O values. The isotope data indicate that foraminifera shells calcify in depth zones that are significantly narrower than the overall vertical distribution of a species would imply

  16. Carbon 13 and oxygen 18 isotope record of the early eocene nammal formation, salt range, pakistan

    International Nuclear Information System (INIS)

    Ghazi, S.; Sajid, Z.

    2014-01-01

    The Nammal Formation is the lowermost unit of the Early Eocene succession in the Salt Range, Pakistan. It is well exposed throughout the Salt Range. The Nammal Formation having 30 to 35 meters thickness is predominantly composed of nodular limestone interbedded with marl and shale. The present study was focussed on stable carbon 13 and oxygen 18 isotopic analysis based on data from two stratigraphically important sections. The samples from the Nilawahan section provided with the delta 13C values varied between 1.34 to -1.56 (VPDB) and values of delta 18O fluctuated between -4.47 to -6.59 (VPDB). Likewise the sample analysis of BadshahPur section exhibited that the delta 13C values changes from 1.09 to -1.65 (VPDB) and delta 18O values range from -4.17 to -6.85 (VPDB). The isotopic records of carbon 13 and oxygen 18 indicated the shallow marine deposition of the Nammal Formation under tropical conditions. It highlighted the palaeo climatic and diagenetic conditions of the Nammal Formation at the time of deposition in the Salt Range region. (author)

  17. A stable isotope study of serpentinization in the Fengtien ophiolite, Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Tzen-Fu Yui; Hsueh-Wen Yeh (Univ. of Hawaii, Honolulu (USA)); Chihming Wang Lee (National Taiwan Univ. (Taiwan))

    1990-05-01

    Detailed H- and O-isotopic studies of serpentinites of Fengtien ophiolite have been made in order to enhance our knowledge on the process of serpentinization. Pseudomorphic lizardites have {delta}{sup 18}O = +3.6{per thousand} and {delta}D = {minus}48 to {minus}49{per thousand}; bladed-mat and foliated antigorites have {delta}{sup 18}O = +3.5 to +5.8{per thousand} and {delta}D = {minus}45 to {minus}69{per thousand}; slickensided antigorites have {delta}{sup 18}O = +4.1 to +4.9{per thousand} and {delta}D = {minus}46 to {minus}50{per thousand}; picrolites have {delta}{sup 18}O = +4.2 to +4.3{per thousand} and {delta}D = {minus}65 to {minus}67{per thousand}; and slickensided chrysotiles have {delta}{sup 18}O = +4.1 to +4.5{per thousand} and {delta}D = {minus}80{per thousand}. It is suggested that lizardite might have formed in an oceanic environment, whereas antigorite and chrysotile have formed in continental environments. These results depict complicated multiple serpentinization processes. Isotopic temperatures calculated using {delta}{sup 18}O values of coexisting fissure-filling minerals range from 325 to 370{degree}C, which are consistent with those derived from phase equilibria involving serpentines. The narrow range of {delta}{sup 18}O and wide range of {delta}D values for antigorite and chrysotile also demonstrate that water/rock ratios during these serpentinizations should not have been high. These Fengtien serpentines fall outside either of the continental domains described by Wenner and Taylor (1973, 1974); and fall within their oceanic domain. We suggest that the domains proposed by Wenner and Taylor (1973, 1974) should be extended and that the terms, especially the continental antigorite and the continental lizardite-chrysotile, should be purely occurrence-descriptive.

  18. The isotopic and chemical evolution of Mount St. Helens

    International Nuclear Information System (INIS)

    Halliday, A.N.; Fallick, A.E.; Dickin, A.P.; Mackenzie, A.B.; Stephens, W.E.

    1983-01-01

    Isotopic and major and trace element analysis of nine samples of eruptive products spanning the history of the Mt. St. Helens volcano suggest three different episodes; (1) 40,000-2500 years ago: eruptions of dacite with epsilonsub(Nd) = +5, epsilonsub(Sr) = -10, variable delta 18 O, 206 Pb/ 204 Pb approx.= 18.76, Ca/Sr approx.= 60, Rb/Ba- approx.= 0.1, La/Yb approx.= 18, (2) 2500-1000 years ago: eruptions of basalt, andesite and dacite with epsilonsub(Nd) = +4 to + 8, epsilonsub(Sr) = -7 to -22, variable delta 18 O (thought to represent melting of differing mantle-crust reservoirs), 206 Pb/ 204 Pb = 18.81-18.87, variable Ca/Sr, Rb/Ba, La/Yb and high Zr, (3) 1000 years ago to present day: eruptions of andesite and dacite with epsilonsub(Nd) = + 6, epsilonsub(Sr) = -13, delta 18 O approx.= 6per mille, variable 206 Pb/ 204 Pb, Ca/Sr approx.= 77, Rb/Ba = 0.1, La/Yb approx.= 11. None of the products exhibit Eu anomalies and all are LREE enriched. There is a strong correlation between 87 Sr/ 86 Sr and differentiation indices. These data are interpreted in terms of a mantle heat source melting young crust bearing zircon and garnet, but not feldspar, followed by intrusion of this crustal reservoir by mantle-derived magma which caused further crustal melting and contaminated the crustal magma system with mafic components. Since 1000 years ago all the eruptions have been from the same reservoir which has displayed a much more gradual re-equilibration of Pb isotopic compositions than other components suggesting that Pb is being transported via a fluid phase. The Nd and Sr isotopic compositions lie along the mantle array and suggest that the mantle underneath Mt. St. Helens is not as depleted as MORB sources. There is no indication of seawater involvement in the source region. (orig.)

  19. Hydrogen and carbon isotopes of petroleum and related organic matter

    International Nuclear Information System (INIS)

    Yeh, H.W.; Epstein, S.

    1981-01-01

    D/H and 13 C/ 12 C ratios were measured for 114 petroleum samples and for several samples of related organic matter. DeltaD of crude oil ranges from -85 to -181 per thousand except for one distillate (-250 per thousand) from the Kenai gas field; delta 13 C of crude oil ranges from -23.3 to -32.5 per thousand. Variation in deltaD and delta 13 C values of compound-grouped fractions of a crude oil is small, 3 and 1.1 per thousand, respectively, and the difference in deltaD and delta 13 C between oil and coeval wax is slight. Gas fractions are 53 to 70 and 22.6 to 23.2 per thousand depleted in D and 13 C, respectively, relative to the coexisting oil fractions. The deltaD and delta 13 C values of the crude oils appear to be largely determined by the isotopic compositions of their organic precursors. The contribution of terrestrial organic debris to the organic precursors of most marine crude oils may be significant. (author)

  20. Deuterium- and 18O-content in the cooling water of power station cooling towers

    International Nuclear Information System (INIS)

    Heimbach, H.; Dongmann, G.

    1976-09-01

    The 0-18/0-16 and D/H isotope ratios of water from two different cooling towers were determined by mass spectrometry. The observed isotope fractionation corresponds to that known from natural evaporation or transpiration processes: cooling tower I: delta(D) = 46.8 per thousand, delta( 18 O) = 7.6 per thousand cooling tower II: delta(D) = 33.9 per thousand delta( 18 O) = 5.7 per thousand Evaluation of simple compartment models of a cooling tower and a distillation device suggests that there exists some isotope discrimination within the open trickling unit of a cooling tower analogous to that in a rectification column. In a real cooling tower, however, this effect is compensated largely by the recycling of the cooling water, resulting only in a small enrichment of the heavy isotopes. This can be understood as the result of three partial effects: 1) a fractionation in the vapor pressure equilibrium, 2) a kinetic effect due to diffusion of the water vapor into a turbulent atmosphere, and 3) an exchange effect which is proportional to relative humidity. This low enrichment of the heavy isotope excludes the technical use of cooling towers as isotope separation devices. (orig.) [de

  1. Measurement of infiltration rates in urban sewer systems by use of oxygen isotopes.

    Science.gov (United States)

    De Bénédittis, J; Bertrand-Krajewski, J L

    2005-01-01

    The paper presents the principle of a method to measure infiltration rates in sewer systems based on the use of oxygen isotopes and its application in Lyon (France). In the urban area of Lyon, significant differences in delta 18O that can reach 3 per thousand are observed between the oxygen isotopic compositions of groundwater originating from Rhone, Saone and from their associated alluvial aquifers. Drinking water supplying Lyon results mainly from pumping in the Rhone alluvial aquifer. Therefore, in some areas, the difference of isotopic composition between wastewater resulting from the consumption of drinking water and local groundwater can be used to measure infiltration in sewer systems. The application in the catchment of Ecully shows that the infiltration flow rate presents strong fluctuations at an hourly scale: it varies between 15 and 40 m3/h. This variability could be explained by non-constant discharges of pumping and by variations of the water level in the sewer.

  2. Stable isotope distribution in continental Maastrichtian vertebrates from the Haţeg Basin, South Carpathians

    Science.gov (United States)

    Bojar, Ana-Voica; Csiki, Zoltan; Grigorescu, Dan

    2010-05-01

    and behaviour of the vertebrates. The large difference observed between the delta 18O and delta 13C of the eggshells and the surrounding mudstones, as well as the preservation of the 9 ‰ difference between the oxygen isotope composition of the Telmatosaurus eggshell and tooth enamel, indicate that diagenesis have not significantly altered the primary isotopic signal. Stable isotope compositions of both calcretes and phosphatic remains suggest warmer conditions during the deposition of the Tuştea sequence than during the deposition of the Sibişel sequence. The intra-tooth delta 18O patterns for Zalmoxes and Allodaposuchus show different magnitudes of isotopic variation, with lower values for Tuştea and higher for Sibişel. The calculated delta 18O body water enrichment for Kallokibotion bajazidi is similar to that found in the living turtle taxa. By contrast, in the case of Allodaposuchus, the isotopic enrichment is higher than for recent taxa. This suggests that, for Allodaposuchus, the body water was less buffered by a watery environment, which probably indicates more time spent outside water (i.e. more terrestrial habit). The delta 18O values for the teeth of Telmatosaurus and Zalmoxes are similar to those of Allodaposuchus, suggesting that, at the investigated sites, the body temperature of both dinosaurs was similar to that of the crocodile. The isotopic composition of calcretes, teeth and eggshells indicates a C3 vegetation and diet with delta 13C values between -27 to -29 ‰ (PDB) and the absence of large-scale habitat partitioning between the dinosaurs.

  3. Oxygen isotope analysis of phosphate: improved precision using TC/EA CF-IRMS.

    Science.gov (United States)

    LaPorte, D F; Holmden, C; Patterson, W P; Prokopiuk, T; Eglington, B M

    2009-06-01

    Oxygen isotope values of biogenic apatite have long demonstrated considerable promise for paleothermometry potential because of the abundance of material in the fossil record and greater resistance of apatite to diagenesis compared to carbonate. Unfortunately, this promise has not been fully realized because of relatively poor precision of isotopic measurements, and exceedingly small size of some substrates for analysis. Building on previous work, we demonstrate that it is possible to improve precision of delta18O(PO4) measurements using a 'reverse-plumbed' thermal conversion elemental analyzer (TC/EA) coupled to a continuous flow isotope ratio mass spectrometer (CF-IRMS) via a helium stream [Correction made here after initial online publication]. This modification to the flow of helium through the TC/EA, and careful location of the packing of glassy carbon fragments relative to the hot spot in the reactor, leads to narrower, more symmetrically distributed CO elution peaks with diminished tailing. In addition, we describe our apatite purification chemistry that uses nitric acid and cation exchange resin. Purification chemistry is optimized for processing small samples, minimizing isotopic fractionation of PO4(-3) and permitting Ca, Sr and Nd to be eluted and purified further for the measurement of delta44Ca and 87Sr/86Sr in modern biogenic apatite and 143Nd/144Nd in fossil apatite. Our methodology yields an external precision of +/- 0.15 per thousand (1sigma) for delta18O(PO4). The uncertainty is related to the preparation of the Ag3PO4 salt, conversion to CO gas in a reversed-plumbed TC/EA, analysis of oxygen isotopes using a CF-IRMS, and uncertainty in constructing calibration lines that convert raw delta18O data to the VSMOW scale. Matrix matching of samples and standards for the purpose of calibration to the VSMOW scale was determined to be unnecessary. Our method requires only slightly modified equipment that is widely available. This fact, and the

  4. Carbon Monoxide Stable Isotopes: Extraction Technique Development and Urban Atmospheric Analysis

    Science.gov (United States)

    Vimont, Isaac Josef

    We have developed an extraction system to analyze isotopes of carbon monoxide (CO). We then analyzed CO isotopes for two years at Indianapolis, IN, USA. These measurements were done at three towers, one of which measured incoming, background air into the city. We quantitatively removed the background signal and determined the urban CO mole fraction and isotopic enhancements. During the winter months, we constrained the isotopic signature and concluded that the majority of CO produced during the winter was produced by fossil fuel combustion. We found that the Indianapolis fossil fuel signature differed from that of studies done in Europe. Further, we performed a limited traffic study to look at CO isotopes from traffic. While this was not conclusive, it did support our hypothesis that a larger fraction of the Indianapolis vehicle fleet may have malfunctioning catalytic systems, which biases the isotopic results, particularly for delta18O. We used the wintertime fossil fuel isotopic signature to help constrain the summertime budget. It was hypothesized that a second source of CO was significant during the summer months. Oxidation of biogenically produced volatile organic compounds (BVOC's) was one possible source. Oxidized BVOC's were consistent with the changes between our winter and summer isotopic source signatures. We then used the isotopic signatures to determine that between zero and sixty percent of the summertime CO budget was produced from oxidized VOC's. This provided the first direct evidence of a larger percentage of urban CO being produced by oxidized VOC's.

  5. Late Cenozoic stable isotope stratigraphy and paleoceanography of DSDP sites from the East equatorial and central north Pacific Ocean

    International Nuclear Information System (INIS)

    Keigwin, L.D. Jr

    1979-01-01

    Stable isotopic analyses of Middle Miocene to Quaternary foraminiferal calcite from east equatorial and central north Pacific DSDP cores have provided much new information on the paleoceanography of the Pacific Neogene. The history of delta 18 O change in planktonic foraminifera reflects the changing isotopic composition and temperature of seawater at the time of test formation. Changes in the isotopic composition of benthonic foraminfera largely reflect changes in the volume of continental ice. Isotopic data from these cores indicates the following sequence of events related to continental galaciation: (1) A permanent Antarctic ice sheet developed late in the Middle Miocene (about 13 to 11.5 m.y. ago). (2) The Late Miocene (about 11.5 to 5 m.y. ago) is marked by significant variation in delta 18 O of about 0.5% throughout, indicating instability of Antarctic ice cap size or bottom-water temperature. (3) The early Pliocene (5 to about 3 m.y. ago) was a time of relative stability in ice volume and bottom-water temperature. (4) Growth of permanent Northern Hemisphere ice sheets is inferred to have begun about 3 m.y. ago. (5) The late Pliocene (3 to about 1.8 m.y. ago) is marked by one major glaciation or bottom-water cooling dated between about 2.1 to 2.3 m.y. (6) There is some evidence that the frequency of glacial-interglacial cycles increased at about 0.9 m.y. (Auth.)

  6. Ice-vapor equilibrium fractionation factor of hydrogen and oxygen isotopes

    DEFF Research Database (Denmark)

    Ellehøj, Mads Dam; Steen-Larsen, Hans Christian; Johnsen, Sigfus Johann

    2013-01-01

    RATIONALE: The equilibrium fractionation factors govern the relative change in the isotopic composition during phase transitions of water. The commonly used results, which were published more than 40 years ago, are limited to a minimum temperature of -33 degrees C. This limits the reliability...... values, with a temperature dependency in accordance with theory for equilibrium fractionation. We obtain the following expressions for the temperature dependency of the fractionation coefficients: ln(alpha(delta 2H)) = 0.2133 - 203.10/T + 48888/T-2 ln(alpha(delta 18O)) = 0.0831 - 49.192/T + 8312.5/T2...... Compared with previous experimental work, a significantly larger for H-2 is obtained while, for O-18, is larger for temperatures below -20 degrees C and slightly lower for temperatures above this. CONCLUSIONS: Using the new values for alpha, a Rayleigh distillation model shows significant changes in both...

  7. Current techniques for the collection and processing of stable isotope data

    International Nuclear Information System (INIS)

    Goodney, D.E.; Kroopnick, P.M.

    1978-01-01

    Recent innovations in instrumentation for stable isotope mass spectrometry are reviewed. 'Off-line' automatic data collection and 'on-line' processing systems have been developed for use with the Nuclide Integrating Ratiometer (IR-2). A BASIC program detects and corrects most instrumental and operator errors and performs all necessary computations. Analysis of the effects of source gas pressure on the accuracy of delta 18 O measurement showed that our Nuclide 3inch-60 0 instrument has a slope of -1.0 0 / 00 /volt over the normal operating range (10-30V), and our Nuclide 6inch-60 0 instrument has a slope of +0.6 0 / 00 /volt. Use of the IR-2 causes the apparent slopes to change to -1.45 0 / 00 /volt and +5 0 / 00 /volt for the 3inch and 6inch instruments, respectively.(auth.)

  8. Carbon and Hydrogen Isotopic Composition of Plant Wax n-Alkanes: A Tool for Characterizing Soil Provenance in Forensic Science

    Science.gov (United States)

    Pedentchouk, N.; Wagner, T.; Jones, M.

    2009-04-01

    Forensic science is an integrative discipline that requires material evidence from diverse sources. Geochemical evidence derived from inorganic and organic substances is becoming increasingly popular among law enforcement agencies in industrialized countries. Previous investigations indicate that the relative distributions of individual plant-derived biomarkers found in soils are linked to the biomarker patterns found in the overlying vegetation. However, identification of soil provenance based on the distribution of plant-derived biomarkers for forensic purposes is inhibited by the fact that a significant number of terrestrial plant species have overlapping biomarker distributions. In order to enhance the resolving power of plant-derived biomarker signal, we propose to enhance the molecular approach by adding a stable isotope component, i.e. the delta13C/deltaD values of individual biomarkers. The first objective of this project is to determine the delta13C/deltaD signatures of n-alkanes derived from various higher plant types commonly growing in the UK. The second objective is to investigate whether the same species/plant types differ isotopically between two locations affected by different weather patterns in the UK: a relatively warmer and drier Norwich, Norfolk and a cooler and wetter Newcastle-upon-Tyne in NE England. The n-C29 alkane data from 14 tree species sampled during July 2007 and August 2008 in Newcastle show a clear negative trend between delta13C and deltaD values. When these data are plotted against each other, the six deciduous angiosperms (delta13C: c. -39 to -35 per mil; deltaD: c. -155 to -130 per mil) are completely separated from four evergreen angiosperms (delta13C: c. -33 to -28 per mil; deltaD: c. -195 to -165 per mil). The four gymnosperm species data plot between those of the deciduous and evergreen angiosperms. Because all 14 species in Newcastle experience the same environmental conditions, we suggest that the observed isotopic

  9. The geochemistry of the stable isotopes of silicon

    International Nuclear Information System (INIS)

    Douthitt, C.B.

    1982-01-01

    One hundred thirty two new measurements of the relative abundances of the stable isotopes of silicon in terrestrial materials are presented. The total variation of delta 30 Si found is 6.2 parts per thousand, centered on the mean of terrestrial mafic and ultramafic igneous rocks, delta 30 Si = -0.4 parts per thousand. Igneous rocks show limited variation; coexisting minerals exhibit small, systematic silicon isotopic fractionations that are roughly 1/3 the magnitude of concomitant oxygen isotopic fractionations at 1150 0 C. In both igneous minerals and rocks, delta 30 Si shows a positive correlation with silicon content, as does delta 18 O. Opal from both sponge spicules and sinters is light, with delta 30 Si = -2.3 and -1.4 parts per thousand respectively. Large delta 30 Si values of both positive and negative sign are reported for the first time from clay minerals, opaline phytoliths, and authigenic quartz. All highly fractionated samples were precipitated from solution at low temperatures; however, aqueous silicon is not measurably fractionated relative to quartz at equilibrium. A kinetic isotope fractionation of approximately 3.5 parts per thousand is postulated to occur during the low temperature precipitation of opal and, possibly, poorly ordered phyllosilicates, with the silicate phase being enriched in 28 Si. This fractionation, coupled with a Rayleigh precipitation model, is capable of explaining most non-magmatic delta 30 Si variations. (author)

  10. The effect of environmental factors on stable isotopic composition of n-alkanes in Mediterranean olive oils

    Science.gov (United States)

    Pedentchouk, Nikolai; Mihailova, Alina; Abbado, Dimitri

    2014-05-01

    Traceability of the geographic origin of olive oils is an important issue from both commercial and health perspectives. This study evaluates the impact of environmental factors on stable C and H isotope compositions of n-alkanes in extra virgin olive oils from Croatia, France, Greece, Italy, Morocco, Portugal, Slovenia, and Spain. The data are used to investigate the applicability of stable isotope methodology for olive oil regional classification in the Mediterranean region. Analysis of stable C isotope composition of n-C29 alkane showed that extra virgin olive oils from Portugal and Spain have the most positive n-C29 alkane delta13C values. Conversely, olive oils from Slovenia, northern and central Italy are characterized by the most negative values. Overall, the n-C29 alkane delta13C values show a positive correlation with the mean air temperature during August-December and a negative correlation with the mean relative humidity during these months. Analysis of stable H isotope composition of n-C29 alkane revealed that the deltaD values are the most positive in olive oils from Greece and Morocco and the most negative in oils from northern Italy. The deltaD values of oils show significant correlation with all the analyses geographical parameters: the mean air temperature and relative humidity during August-December, the total amount of rainfall (the same months) and the annual deltaD values of precipitation. As predictor variables in the Categorical Data Analysis, the n-C29 alkane deltaD values show the most significant discriminative power, followed by the n-C29 alkane delta13C values. Overall, 93.4% of olive oil samples have been classified correctly into one of the production regions. Our findings suggest that an integrated analysis of C and H isotope compositions of n-alkanes extracted from extra virgin olive oil could become a useful tool for geographical provenancing of this highly popular food commodity.

  11. Strontium isotopic and trace element geochemistry of the saddle mountains and Grande Ronde Basalts of the Columbia River Basalt Group

    International Nuclear Information System (INIS)

    Nelson, D.O.

    1980-01-01

    The Columbia River Basalt (CRB) group displays significant variations in major and trace element and Sr isotopic compositions. These compositions reflect complex and variable origins for the CRB magmas. Among the most varied is the Saddle Mountains Basalt (SMB) in which Sr ratios vary from 0.7078 to 0.7147 +- 0.002. The higher ratios reflect contamination through consistent correlations with major element compositions. Modeling suggests contamination by assimilation of 4.4 to 9.4 wt % of radiogenic crustal rocks. High delta 18 O values (up to +7.68 per mil) support the model. Age and field relations suggest that the contamination flowrocks are not the result of progressive contamination of a single magma, but rather reflect the contamination of independent magmas during this ascent

  12. Oxygen isotope variability in snow from western Dronning Maud Land, Antarctica and its relation to temperature

    International Nuclear Information System (INIS)

    Helsen, M.M.; Wal, R.S.W. van de; Broeke, M.R. van den; As, D. van; Reijmer, C.H.; Meijer, H.A.J.

    2005-01-01

    This paper presents (delta) 18 O records from snow pits from four locations in Dronning Maud Land, Antarctica that contain at least four annual cycles. The aim of the study was to analyse in detail these records as well as the prevailing temperatures during accumulation in order to infer to what extent isotopic composition in this area can be interpreted as temperature information. The original seasonal amplitudes of the isotope records were reconstructed by use of a simple back-diffusion model. Automatic weather station data were used to describe the accumulation history and the near-surface temperatures; the temperatures at the atmospheric level of snow formation were inferred from a regional climate model. The results show that the strongly intermittent nature of the accumulation in this area can result in the exclusion of entire seasons from the isotope records. The temperature records also reveal that the oxygen isotope records in these snow pits are biased towards higher temperatures, since snowfall conditions are associated with higher temperatures. This effect is greatest at low temperatures. A comparison between the seasonal extreme isotopic and temperature values points out that on timescales of seasons to several years, isotopic variability cannot be interpreted with confidence as temperature changes at the accumulation sites

  13. A stable isotope approach for the quantification of sewer infiltration.

    Science.gov (United States)

    Kracht, Oliver; Gresch, Markus; Gujert, Willi

    2007-08-15

    Extraneous flows in wastewater collection systems are conventionally evaluated solely on the consideration of discharge hydrographs, which often involves a great degree of subjectivity and oversimplification. To obtain reliable information on the material fluxes within the urban environment, the use of intrinsic tracers can be the optimal choice. We demonstrate the successful use of naturally occurring stable isotopes of water (18O/16O and D/H) to accurately quantify extraneous discharge of groundwater in a combined sewer network. Fresh water supply from a distant hydrological regime provided usable isotopic separations between drinking water (proxy for real foul sewage) and local groundwater (proxy for sewer infiltration) of 1.8 per thousand in delta18O and 11.7 per thousand in 62H. Diurnal variation of wastewater isotopic composition reflected both the varying rates of foul sewage production and irregular dispersion effects in the pipe network. The latter suggest the existence of larger cumulative backwater zone volumes, which have not been attended to yet. Infiltrating groundwater contributed 39% (95% confidence interval = +/- 2.5%) of the total daily dry weather wastewater discharge. This paper discusses all relevant aspects for practical application of the method. It presents a comprehensive framework for uncertainty analysis and details on the detection and discrimination of possibly interfering effects.

  14. Environmental isotopes in the aquifers of the North Western Sahara

    International Nuclear Information System (INIS)

    Conrad, G.

    1975-09-01

    The isotopic composition of single rains at Beni-Abbes (Algeria) has been determined from 1964 to 1975. The weighed mean delta 18 O value is -3.54 %o vs. SMOW for all rains, -6.29 for rains higher than 10 mm. Only these more intense rains are believed to contribute significantly to groundwater recharge. Tritium content of precipitation varies from 900 TU in a 1964 rain, to 235 in 1967, 215 in 1968 and about 50 in 1972. The isotopic and chemical composition of water from a small salt lake nearby Beni-Abbes show variations depending on the evaporation rate and on the amount and origin of inflow. Groundwater in the Western Ground Erg contain significant amount of tritium, indicating recent recharge. The water is however submitted to evaporation as indicated by its 18 O and deuterium content. The so-called Continental Intercalaire aquifer, which extends over most of the Sahara desert, appears to be presently recharged in the outcropping areas like in Tidikelt, as shown by tritium and 14 C, and by the Western Ground Erg aquifer in the Gourara area, as shown by stable isotopes

  15. Investigation of regional geohydrology south of Great Slave Lake, Canada, utilizing natural sulphur and hydrogen isotope variations

    International Nuclear Information System (INIS)

    Weyer, K.U.; Horwood, W.C.; Krouse, H.R.

    1979-01-01

    The well-defined topographic, geological, and orographic setting in the area south of Great Slave Lake, in Canada's North-West Territory (N.W.T.), is favourable for a meaningful investigation of the local and regional groundwater flow sysems in the area of the Mississippi Valley type lead-zinc deposits at Pine Point. Chemical and isotope (delta 34 S, deltaD) investigations have provided supporting evidence for conceptual models of groundwater flow. The range of the deltaD values encountered (-111 to -205 per mille SMOW) indicates that the hydrodynamic systems convey meteoric waters. Differences in deltaD values of water samples were used to elucidate the hydrological relationship between groundwater and a major river in a karst area. The ore bodies at Pine Point are engulfed in a reducing hydrosphere. Sulphur species, derived from gypsum layers by regional groundwater flow, are instrumental in maintaining the reducing conditions. There is evidence that the reduction of sulphate to sulphide is caused by bacteria. Microbiological sulphate reduction, rather than isotopic exchange processes, is also responsible for shifts of measured delta 34 S values in dissolved sulphates. After correction for those shifts, four different sources for dissolved sulphate were identified. In addition to supporting the conceptual model of regional groundwater flow in this area, the isotopic data also help to delineate hydrological features on a more local scale. (author)

  16. High resolution stable isotopes and elemental analysis on benthic foraminifera: a 4000 yr BP record from the ria de Muros (NW Spain)

    Science.gov (United States)

    Pena, L. D.; Francés, G.; Diz, P.; Nombela, M. A.; Alejo, I.

    2003-04-01

    Carbon and oxygen stable isotopes and ICP-OES elemental ratio concentrations (Mg/Ca, Sr/Ca, Ba/Ca) from core EUGC-3B (42 45.10'N; 9 02.23'W, at 38 m.b.s.l. and 410 cm length) were measured over monospecific benthic foraminiferal samples (Nonion fabum) ranging over the last 4500 yr BP. From the oldest analysed sample (289 cm) to the core top, stable isotopes signal shows that the whole record can be separated into 4 intervals lasting each of them about 1000 yr. The lowermost interval (4300-3000 yr BP) is characterized by relatively stable delta 18O values (mean 1.77 per mil). Delta 13C is relatively low except for a maximum around 3300 cal BP (-1.50 per mil). An abrupt decrease down to the minimum value in delta 13C (-4.41 per mil) is accomplished in approximately 200 yr. Mg/Ca and Ba/Ca match perfectly this event, both of them showing the respective maxima values. Sr/Ca has a very similar behaviour to that of delta 13C but with smoother fluctuations. We attribute high values of delta 13C, Sr/Ca and Ba/Ca to periods of enhanced coastal productivity, probably due to reinforced upwelling events in the region. According to Mg/Ca signal this reinforcement took place during a relatively warmer period. The most remarkable feature during the two next periods (3000-1900 yr BP and 1900-1000 yr BP) consists of a stepwise increase of delta 13C values punctuated by a sharp decrease at the end of each interval. All the remaining proxies exhibit a nearly constant trend over these intervals. Each period can be interpreted as a weak enhance of marine productivity that the system does not hold up and finally aborts. The most recent interval represents the establishment of current conditions in the coastal system. The most conspicuous event from this interval consists of an abrupt decrease of the delta 18O that lasted for 300 yr. This event could be correlated with the well recognized warm climatic event known as the Medieval Warm Period. However the Mg/Ca ratio does not show high

  17. Stable isotope quality assurance using the 'calibrated IRMS' strategy.

    Science.gov (United States)

    Meijer, Harro A J

    2009-06-01

    Procedures in our laboratory have always been directed towards complete understanding of all processes involved and corrections needed etc., instead of relying fully on laboratory reference materials. This rather principal strategy (or attitude) is probably not optimal in the economic sense, and is not necessarily more accurate either. Still, it has proven to be very rewarding in its capability to detect caveats that go undiscovered in the standard way of measurement, but that do influence the accuracy or reliability of the measurement procedure. An additional benefit of our laboratory procedures is that it makes us capable of assisting the International Atomic Energy Agency (IAEA) with primary questions like mutual scale assignments and comparison of isotope ratios of the same isotope in different matrices (like delta(18)O in water, carbonates and atmospheric CO(2)), establishment of the (17)O-(18)O relation, and the replenishment of the calibration standards. Finally, for manual preparation systems with a low sample throughput (and thus only few reference materials analysed) it may well be the only way to produce reliable results.

  18. Organochlorine pollutants and stable isotopes in resident and migrant passerine birds from northwest Michoacán, Mexico.

    Science.gov (United States)

    Mora, Miguel A

    2008-10-01

    Although concentrations of organochlorine compounds (OCs) in birds from most of the United States and Canada have decreased over the last 30 years, there is still concern that migrant birds might be exposed to elevated concentrations of OCs during migration in Latin America. The Lerma-Chapala Basin in west-central Mexico is an important migration corridor and wintering area for many species. The objectives of this study were to assess if resident and migrant birds wintering in western Michoacán, Mexico accumulated elevated concentrations of OCs during fall and spring and to determine if the stable isotopes delta(15)N, delta(13)C, and deltaD could be used to predict burdens and origins of DDE accumulation. Resident and migrant passerine insectivorous birds were collected during fall and spring (2001-2002) in northwest Michoacán, near Chapala Lake, Mexico. The carcasses were analyzed for OCs and tail feathers were analyzed for stable isotopes delta(15)N, delta(13)C, and deltaD. The OCs detected in more than 50% of the samples were: oxychlordane (79%), p,p'-DDE (100%), p,p'-DDT (57%), and total PCBs (100%). p,p'-DDE was the OC detected at the highest concentrations, whereas residues of other OCs were near or below detection limits. Overall, there were no significant differences in concentrations of OCs between seasons or between resident and migrant birds. Concentrations of DDE and oxychlordane were somewhat higher in migrant and resident birds during spring than in fall; however, concentrations were significantly different only for oxychlordane. Two resident birds collected in fall and spring had DDE residues >10 microg/g wet weight in carcass. There were no significant differences in delta(13)C and delta(15)N values among species, between seasons, or between migrant and resident birds. However, deltaD values were clearly different between species and helped differentiate migrant from resident birds. deltaD values also were negatively and significantly correlated

  19. Isotope effects accompanying evaporation of water from leaky containers.

    Science.gov (United States)

    Rozanski, Kazimierz; Chmura, Lukasz

    2008-03-01

    Laboratory experiments aimed at quantifying isotope effects associated with partial evaporation of water from leaky containers have been performed under three different settings: (i) evaporation into dry atmosphere, performed in a dynamic mode, (ii) evaporation into dry atmosphere, performed in a static mode, and (iii) evaporation into free laboratory atmosphere. The results demonstrate that evaporative enrichment of water stored in leaky containers can be properly described in the framework of the Craig-Gordon evaporation model. The key parameter controlling the degree of isotope enrichment is the remaining fraction of water in the leaking containers. Other factors such as temperature, relative humidity, or extent of kinetic fractionation play only minor roles. Satisfactory agreement between observed and predicted isotope enrichments for both (18)O and (2)H in experiments for the case of evaporation into dry atmosphere could be obtained only when molecular diffusivity ratios of isotope water molecules as suggested recently by Cappa et al. [J. Geophys. Res., 108, 4525-4535, (2003).] were adopted. However, the observed and modelled isotope enrichments for (2)H and (18)O could be reconciled also for the ratios of molecular diffusivities obtained by Merlivat [J. Chem. Phys., 69, 2864-2871 (1978).], if non-negligible transport resistance in the viscous liquid sub-layer adjacent to the evaporating surface is considered. The evaporation experiments revealed that the loss of mass of water stored in leaky containers in the order of 1%, will lead to an increase of the heavy isotope content in this water by ca. 0.35 and 1.1 per thousand, for delta (18)O and delta (2)H, respectively.

  20. Maintaining high precision of isotope ratio analysis over extended periods of time.

    Science.gov (United States)

    Brand, Willi A

    2009-06-01

    Stable isotope ratios are reliable and long lasting process tracers. In order to compare data from different locations or different sampling times at a high level of precision, a measurement strategy must include reliable traceability to an international stable isotope scale via a reference material (RM). Since these international RMs are available in low quantities only, we have developed our own analysis schemes involving laboratory working RM. In addition, quality assurance RMs are used to control the long-term performance of the delta-value assignments. The analysis schemes allow the construction of quality assurance performance charts over years of operation. In this contribution, the performance of three typical techniques established in IsoLab at the MPI-BGC in Jena is discussed. The techniques are (1) isotope ratio mass spectrometry with an elemental analyser for delta(15)N and delta(13)C analysis of bulk (organic) material, (2) high precision delta(13)C and delta(18)O analysis of CO(2) in clean-air samples, and (3) stable isotope analysis of water samples using a high-temperature reaction with carbon. In addition, reference strategies on a laser ablation system for high spatial resolution delta(13)C analysis in tree rings is exemplified briefly.

  1. A method for investigating population declines of migratory birds using stable isotopes: origins of harvested lesser scaup in North America.

    Directory of Open Access Journals (Sweden)

    Keith A Hobson

    2009-11-01

    Full Text Available Elucidating geographic locations from where migratory birds are recruited into adult breeding populations is a fundamental but largely elusive goal in conservation biology. This is especially true for species that breed in remote northern areas where field-based demographic assessments are logistically challenging.Here we used hydrogen isotopes (deltaD to determine natal origins of migrating hatch-year lesser scaup (Aythya affinis harvested by hunters in the United States from all North American flyways during the hunting seasons of 1999-2000 (n = 412 and 2000-2001 (n = 455. We combined geospatial, observational, and analytical data sources, including known scaup breeding range, deltaD values of feathers from juveniles at natal sites, models of deltaD for growing-season precipitation, and scaup band-recovery data to generate probabilistic natal origin landscapes for individual scaup. We then used Monte Carlo integration to model assignment uncertainty from among individual deltaD variance estimates from birds of known molt origin and also from band-return data summarized at the flyway level. We compared the distribution of scaup natal origin with the distribution of breeding population counts obtained from systematic long-term surveys.Our analysis revealed that the proportion of young scaup produced in the northern (above 60 degrees N versus the southern boreal and Prairie-Parkland region was inversely related to the proportions of breeding adults using these regions, suggesting that despite having a higher relative abundance of breeding adults, the northern boreal region was less productive for scaup recruitment into the harvest than more southern biomes. Our approach for evaluating population declines of migratory birds (particularly game birds synthesizes all available distributional data and exploits the advantages of intrinsic isotopic markers that link individuals to geography.

  2. A system for high-quality CO2 isotope analyses of air samples collected by the CARIBIC Airbus A340-600.

    Science.gov (United States)

    Assonov, S; Taylor, P; Brenninkmeijer, C A M

    2009-05-01

    In 2007, JRC-IRMM began a series of atmospheric CO2 isotope measurements, with the focus on understanding instrumental effects, corrections as well as metrological aspects. The calibration approach at JRC-IRMM is based on use of a plain CO2 sample (working reference CO2) as a calibration carrier and CO2-air mixtures (in high-pressure cylinders) to determine the method-related correction under actual analytical conditions (another calibration carrier, in the same form as the samples). Although this approach differs from that in other laboratories, it does give a direct link to the primary reference NBS-19-CO2. It also helps to investigate the magnitude and nature for each of the instrumental corrections and allows for the quantification of the uncertainty introduced. Critical tests were focused on the instrumental corrections. It was confirmed that the use of non-symmetrical capillary crimping (an approach used here to deal with small samples) systematically modifies delta13C(CO2) and delta18O(CO2), with a clear dependence on the amount of extracted CO2. However, the calibration of CO2-air mixtures required the use of the symmetrical dual-inlet mode. As a proof of our approach, we found that delta13C(CO2) on extracts from mixtures agreed (within 0.010 per thousand) with values obtained from the 'mother' CO2 used for the mixtures. It was further found that very low levels of hydrocarbons in the pumping systems and the isotope ratio mass spectrometry (IRMS) instrument itself were critical. The m/z 46 values (consequently the calculated delta18O(CO2) values) are affected by several other effects with traces of air co-trapped with frozen CO2 being the most critical. A careful cryo-distillation of the extracted CO2 is recommended. After extensive testing, optimisation, and routine automated use, the system was found to give precise data on air samples that can be traced with confidence to the primary standards. The typical total combined uncertainty in delta13C(CO2) and

  3. Moisture source in the Hyblean Mountains region (south-eastern Sicily, Italy): Evidence from stable isotopes signature

    Energy Technology Data Exchange (ETDEWEB)

    Grassa, Fausto [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa, 153, 90146 Palermo (Italy)]. E-mail: f.grassa@pa.ingv.it; Favara, Rocco [Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo, Via Ugo La Malfa, 153, 90146 Palermo (Italy); Valenza, Mariano [Dipartimento CFTA, Universita di Palermo, Palermo, Via Archirafi, 36, 90123, Palermo (Italy)

    2006-12-15

    Here the authors present results of an isotope study on precipitation collected during a 2-a period from a rain-gauge network consisting of 6 stations located at different elevations in the Hyblean Mountains (HM) region, in south-eastern Sicily. The slope of the local meteoric water line ({delta}D = 6.50 {delta} {sup 18}O + 9.87) obtained for the region suggests that precipitation is affected by evaporation during rainfall events. The main variations in rainwater isotope composition are due to seasonal effects and elevation. An average {sup 2}H excess value of +21.2 per mille was found for precipitation events less affected by evaporation (i.e. when the rainfall was >65 mm/month). The spatial distribution of O isotope composition of precipitation shows a negative gradient from east and south to the inner areas. The depositional rate of Cl, used as a tracer of the origin of air masses, is highest at the coastal rain-gauges (SR and MRG stations) and lowest on the northern flank of the HM region (SC station). Based on these findings, a model is proposed for the origin of precipitation in the HM region, which assumes that a Mediterranean-derived component is the main source of moisture in the studied area. D/H and {sup 18}O/{sup 16}O ratios of inferred meteoric recharge waters were also compared with the isotope composition of waters collected from the main local springs and wells. The best linear fit of the {delta} {sup 18}O vs {delta}D relationship for Hyblean groundwater is {delta}D = 4.85 {delta} {sup 18}O-2.01. The enrichment of heavy isotopes in Hyblean groundwater is probably due to evaporation occurring after precipitation events or to a recharging contribution from surface waters (lakes or rivers) enriched in heavy isotopes.

  4. Using Stable Isotope Geochemistry to Determine Changing Paleohydrology and Diagenetic Alteration in the Late Cretaceous Kaiparowits Formation, UT USA

    Science.gov (United States)

    Yamamura, Daigo

    The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed. Despite the difference in facies and sedimentary architecture, the isotope composition does not change significantly at 110 m from the base of the formation. Among the well-preserved cement samples, stable isotope composition indicates a significant hydrologic change within the informal Middle unit; a 6.37‰ depletion in delta13C and 3.30‰ enrichment in delta 18O occurs at 300 m above the base of the formation. The isotope values indicate that the sandstone cements below 300 m were precipitated in a mixing zone between marine and terrestrial groundwater, whereas the cements in upper units were precipitated in a terrestrial groundwater. Despite the difference in physical appearance (i.e. color and shape), the isotopic compositions of cements in concretions are similar to well-cemented sandstone bodies in similar stratigraphic positions. Isotope compositions of the host rock are similar to that of mudrock and weathered sandstone, suggesting the origin of cementing fluids for the sandstone and concretions were the same indicating that: 1) the concretions were formed in shallow groundwater and not related to the groundwater migration, or 2) all cements in upper Kaiparowits Formation are precipitated or altered during later stage groundwater migration. Average delta18Oc from each taxon show the same trend as the delta18Op stratigraphic change, suggesting delta18Oc is still useful as a

  5. Variation in the isotopic content of precipitation with altitude

    International Nuclear Information System (INIS)

    Stowhas, L.; Silva, C.; Moser, H.; Stichler, W.

    1975-03-01

    Monthly precipitation and single storms have been collected during three years at 12 stations along a W-E profile in Chile, going from Juan Fernandez Islands to Valparaiso, Santiago and Infiernillo in the Andes, and analysed for their deuterium content. The deltaD values are correlated with the altitude of the station, the mean temperature - which also largely depends on the altitude - and the distance from the sea. The correlation parameters show however important variations from year to year and even more from month to month. For instance, in the stretch Santiago (520 m a.s.l.) - La Parva (2680 m) the mean isotopic gradient with altitude were: -1.84 deltaD per mil/100 m in 1970, -1.09 in 1971 and -2.0 in 1972. The low value observed in 1971 could be a consequence of the peculiar weather characteristics of this unusually dry year. In the stretch from the coast to Santiago the trend of the isotopic composition of precipitation is more complicated, because the so-called continental effect is superimposed to the altitude effect. The deuterium content variations have been also determined in snowpack profiles at La Parva station. The results show that snow melting occurs slowly at the bottom during the whole winter, at the expenses of the heat stored during summer in the soil. The melting of the surface snow layers only starts at the end of the winter and then proceeds very fast

  6. Covariance of oxygen and hydrogen isotopic composition in plant water: Species effects

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, L.W.; DeNiro, M.J. (Univ. of California, Los Angeles (United States))

    1989-12-01

    Leaf water becomes enriched in the heavy isotopes of oxygen and hydrogen during evapotranspiration. The magnitude of the enrichment has been shown to be influenced by temperature and humidity, but the effects of species-specific factors on leaf water enrichment of D and {sup 18}O have not been studied for different plants growing together. To learn whether leaf water enrichment patterns and processes for D and {sup 18}O are different for individual species growing under the same environmental conditions the authors tested the proposal that leaf waters in plants with crassulacean acid metabolism (CAM) show high sloped (m in the leaf water equation {delta}D = m {delta}{sup 18}O + b) than in C{sub 3} plants. They determined the relationships between the stable hydrogen ({delta}D) and oxygen ({delta}{sup 18}O) isotope ratios of leaf waters collected during the diurnal cycle of evapotranspiration for Yucca schidigera, Ephedra aspera, Agave deserti, Prunus ilicifolia, Yucca whipplei, Heteromeles arbutifolia, Dyckia fosteriana, Simmondsia chinensis, and Encelia farinosa growing at two sites in southern California. The findings indicate that m in the aforementioned equation is related to the overall residence time for water in the leaf and proportions of water subjected to repeated evapotranspiration enrichments of heavy isotopes.

  7. Abundance and Isotopic Composition of Gases in the Martian Atmosphere: First Results from the Mars Curiosity Rover

    Science.gov (United States)

    Mahaffy, Paul; Webster, Chris R.; Atreya, Sushil K.; Franz, Heather; Wong, Michael; Conrad, Pamela G.; Harpold, Dan; Jones, John J.; Leshin, Laurie, A.; Manning, Heidi; hide

    2013-01-01

    Repeated measurements of the composition of the Mars atmosphere from Curiosity Rover yield a (40)Ar/N2 ratio 1.7 times greater and the (40)Ar/(36)Ar ratio 1.6 times smaller than the Viking Lander values in 1976. The unexpected change in (40)Ar/N2 ratio probably results from different instrument characteristics although we cannot yet rule out some unknown atmospheric process. The new (40)Ar/(36)Ar ratio is more aligned with Martian meteoritic values. Besides Ar and N2 the Sample Analysis at Mars instrument suite on the Curiosity Rover has measured the other principal components of the atmosphere and the isotopes. The resulting volume mixing ratios are: CO2 0.960(+/- 0.007); (40)Ar 0.0193(+/- 0.0001); N2 0.0189(+/- 0.0003); O2 1.45(+/- 0.09) x 10(exp -3); and CO 5.45(+/- 3.62) x 10(exp 4); and the isotopes (40)Ar/(36)Ar 1.9(+/- 0.3) x 10(exp 3), and delta (13)C and delta (18)O from CO2 that are both several tens of per mil more positive than the terrestrial averages. Heavy isotope enrichments support the hypothesis of large atmospheric loss. Moreover, the data are consistent with values measured in Martian meteorites, providing additional strong support for a Martian origin for these rocks.

  8. Variations in the D/H and 18O/16O ratios in cellulose extracted from a peat bog core

    International Nuclear Information System (INIS)

    Brenninkmeijer, C.A.M.; Mook, W.G.; Geel, B. van

    1982-01-01

    A peat core from a raised bog covering the period 3100 to 2400 14 C years B.P. has been analysed for D/H and 18 O/ 16 O ratios. These analyses were applied to cellulose, extracted from 56 successive layers of 1 cm thickness. D/H ratios were determined for the carbon bonded hydrogen; 18 O/ 16 O analyses were performed by applying a new method. For the interpretation of the results obtained on peat, the isotopic ratios of 11 living bog plant species were measured, showing a relatively large scatter. Most pronounced is a depletion in D of about 25per mille and in 18 O of about 5per mille of the Sphagnum mosses relative to the vascular bog plants. This different isotopic composition is reflected by the deltaD and delta 18 O records of the peat core, because the abundance of the remains of non-vascular plants is variable. If this effect is taken account of, the remaining deltaD variations appear to be too large to be attributed to variations in the isotopic compositions of precipitation. As palaeoclimatic indicators the D/H and 18 O/ 16 O ratio qualitatively agree with the pollen analytical evidence for the climatic deterioration of the Subboreal-Subatlantic transition. (orig.)

  9. Non-mass-dependent fractionation of sulfur and oxygen isotopes during UV photolysis of sulfur dioxide

    Science.gov (United States)

    Pen, Aranh

    fractionation observed in nature, to quantify anomalous isotope fractionations for both sulfur and oxygen, and to observe fractionation correlations between the two elements. We have measured the anomalous fractionations of sulfur and oxygen isotopes (delta33S, delta34S, delta 36S, delta17O and delta18O) that occur during photodissociation of gaseous SO2 in the 180-400 nm wavelength range and I report delta33S', delta34 S', delta36S', delta17O', and delta 18O', and the corresponding anomalous isotope fractionations Delta 33S, Delta36S, and Delta17O. Our experimental SO2 isotope data support the idea that anomalous sulfur signatures in barite and pyrite (formed before ˜2.1 Gya) resulted from gas-phase reactions taking place in the Earth's early atmosphere. Our results agree qualitatively with Lyons' photochemical self-shielding model of SO2, while our Delta36S/Delta33S slope of -0.74 agrees in sign, but not in magnitude with Lyons' slope of -3 (Lyons, 2008). Our result is in closer agreement to Farquhar et al.'s Archean mineral Delta36S/Delta33S slope of -0.9 (Farquhar et al., 2001).

  10. Isotope signatures in winter moulted feathers predict malaria prevalence in a breeding avian host.

    Science.gov (United States)

    Yohannes, Elizabeth; Hansson, Bengt; Lee, Raymond W; Waldenström, Jonas; Westerdahl, Helena; Akesson, Mikael; Hasselquist, Dennis; Bensch, Staffan

    2008-11-01

    It is widely accepted that animal distribution and migration strategy might have co-evolved in relation to selection pressures exerted by parasites. Here, we first determined the prevalence and types of malaria blood parasites in a breeding population of great reed warblers Acrocephalus arundinaceus using PCR. Secondly, we tested for differences in individual feather stable isotope signatures (delta (13)C, delta (15)N, deltaD and delta (34)S) to investigate whether malaria infected and non-infected birds had occupied different areas in winter. We show that birds moulting in Afro-tropical habitats with significantly higher delta (13)C and delta (15)N but lower deltaD and delta(34)S values were more frequently infected with malaria parasites. Based on established patterns of isotopic distributions, our results indicate that moulting sites with higher incidence of malaria are generally drier and situated further to the north in West Africa than sites with lower incidence of malaria. Our findings are pertinent to the general hypothesis that animal distribution and particularly avian migration strategy might evolve in response to selection pressures exerted by parasites at different geographic scales. Tradeoffs between investment in energy demanding life history traits (e.g. migration and winter moult) and immune function are suggested to contribute to the particular choice of habitat during migration and at wintering sites.

  11. Geographic variation of strontium and hydrogen isotopes in avian tissue: implications for tracking migration and dispersal.

    Directory of Open Access Journals (Sweden)

    Megan J Sellick

    Full Text Available Isotopes can provide unique solutions to fundamental problems related to the ecology and evolution of migration and dispersal because prior movements of individuals can theoretically be tracked from tissues collected from a single capture. However, there is still remarkably little information available about how and why isotopes vary in wild animal tissues, especially over large spatial scales.Here, we describe variation in both stable-hydrogen (deltaD(F and strontium ((87Sr/(86Sr(F isotopic compositions in the feathers of a migratory songbird, the Tree Swallow (Tachycineta bicolor, across 18 sampling sites in North America and then examine potential mechanisms driving this variation. We found that deltaD(F was correlated with latitude of the sampling site, whereas (87Sr/(86Sr(F was correlated with longitude. deltaD(F was related to deltaD of meteoric waters where molting occurred and (87Sr/(86Sr(F was influenced primarily by the geology in the area where feathers were grown. Using simulation models, we then assessed the utility of combining both markers to estimate the origin of individuals. Using 13 geographic regions, we found that the number of individuals correctly assigned to their site of origin increased from less than 40% using either deltaD or (87Sr/(86Sr alone to 74% using both isotopes.Our results suggest that these isotopes have the potential to provide predictable and complementary markers for estimating long-distance animal movements. Combining isotopes influenced by different global-scale processes may allow researchers to link the population dynamics of animals across large geographic ranges.

  12. Carbon and hydrogen isotope fractionation under continuous light: implications for paleoenvironmental interpretations of the High Arctic during Paleogene warming.

    Science.gov (United States)

    Yang, Hong; Pagani, Mark; Briggs, Derek E G; Equiza, M A; Jagels, Richard; Leng, Qin; Lepage, Ben A

    2009-06-01

    The effect of low intensity continuous light, e.g., in the High Arctic summer, on plant carbon and hydrogen isotope fractionations is unknown. We conducted greenhouse experiments to test the impact of light quantity and duration on both carbon and hydrogen isotope compositions of three deciduous conifers whose fossil counterparts were components of Paleogene Arctic floras: Metasequoia glyptostroboides, Taxodium distichum, and Larix laricina. We found that plant leaf bulk carbon isotopic values of the examined species were 1.75-4.63 per thousand more negative under continuous light (CL) than under diurnal light (DL). Hydrogen isotope values of leaf n-alkanes under continuous light conditions revealed a D-enriched hydrogen isotope composition of up to 40 per thousand higher than in diurnal light conditions. The isotope offsets between the two light regimes is explained by a higher ratio of intercellular to atmospheric CO(2) concentration (C (i)/C (a)) and more water loss for plants under continuous light conditions during a 24-h transpiration cycle. Apparent hydrogen isotope fractionations between source water and individual lipids (epsilon(lipid-water)) range from -62 per thousand (Metasequoia C(27) and C(29)) to -87 per thousand (Larix C(29)) in leaves under continuous light. We applied these hydrogen fractionation factors to hydrogen isotope compositions of in situ n-alkanes from well-preserved Paleogene deciduous conifer fossils from the Arctic region to estimate the deltaD value in ancient precipitation. Precipitation in the summer growing season yielded a deltaD of -186 per thousand for late Paleocene, -157 per thousand for early middle Eocene, and -182 per thousand for late middle Eocene. We propose that high-latitude summer precipitation in this region was supplemented by moisture derived from regionally recycled transpiration of the polar forests that grew during the Paleogene warming.

  13. Macro elements and isotopic composition survey in a hydrographic basin in the Center Amazon

    International Nuclear Information System (INIS)

    Cunha Senna, Hillandia Brandao da.

    1992-07-01

    The study was conducted in a 3.5 Km 2 watershed located approximately 60 Km north from Manaus. It's main objective was to quantify major elements inputs through rainfall and outputs via river run-off, and to study the water routing by using water stable isotopes. The sampling was conducted in four different pluviometers and in the main channel of the watershed. The major elements Ca ++ , K + , P and Al do not showed significant temporal variability, however with a lower concentration in relation to other studies. The major elements budget showed a net gain of Mg + , Na ++ , Na ++ and N O 3 - , or the input fluxes were higher than the output fluxes. On the other hand, there was a net loss of K + , Al, Fe, and Cl - . The average values of the delta 18 O and delta Deuterium of the rain water was equal to -3,3% and -14,8% respectively. For the river water the average concentration was lighter than the rain, being equal to -5,1% and -26,1%. (author). 87 refs., 15 figs., 11 tabs

  14. Reconstruction of pH and partial pressure of carbon dioxide during the Mesozoic era period using boron and oxygen isotopic compositions of fresh ammonoids & nautiloids

    Science.gov (United States)

    Kawahata, Hodaka; Fukushima, Ayaka; Moriya, Kazuyori; Ishikawa, Tsuyoshi; Suzuki, Atsushi; Tanabe, Kazushige

    2013-04-01

    The increase of partial pressure of carbon dioxide (pCO2) in the atmosphere induces global warming and ocean acidification at the modern condition. The reconstruction of pCO2 during the geological time is required together with proxy calibration by laboratory experiments to predict the future environments. Boron isotopic ratio is an excellent proxy for pH and the relevant partial pressure of carbon dioxide in the seawater (PCO2). This study is the first to quantify pH dependence of delta 11B of the ammonoids and nautiloids mainly in the Cretaceous and in Jurassic (70-162 Ma), which are expected to be much warmer due to higher PCO2. However, no reliable reconstruction data using foraminiferal delta 11B before Cenozoic era has been reported. We used the very fresh aragonite shells of ammonoids and nautiloids by big advantages. Since aragonite changes into secondary calcite by diagenesis, it is easy and effective to identify the degree of alteration at each sample by measuring calcite/aragonite ratio. Also we carefully conducted the assessment of secondary alteration from three perspectives: 1) Determination of calcite/aragonite ratio by X-ray diffraction (XRD), 2) Observation of microstructures of the nacreous layers by scanning electron microscope (SEM), and 3) Measurement of trace element contents and stable isotope ratios. We conducted high precision boron isotope analysis of biogenic carbonates with +/- 0.1 per mil reproducibility by adopting positive thermal ionization mass spectrometry (P-TIMS) methods. Also we analyzed delta 18O to estimate paleo-temperature, at which biogenic aragonite was formed. Combination of delta 11B and delta 18O of biogenic aragonite in 80 Ma and 86 Ma revealed that deeper dwellers showed lower delta 11B values, which corresponded to lower pH. This feature is consistent with those observed in the modern vertical water column. The respective shallow water temperature was 19.7 and 19.1 centigrade. Based on these results, the

  15. Stable isotopic variations in foraminiferal test from Arabian Sea and its relation to the annual south-west monsoonal rainfall over the Indian subcontinent

    Digital Repository Service at National Institute of Oceanography (India)

    Borole, D.V.

    did not change significantly during the study period. As the monsoonal rainfall of 1987 over the subcontinent was anomalously weak in nature, the above observational finding of low swing in delta 18O values underlines the use of seasonal variability...

  16. Rb-Sr, K-Ar, and stable isotope evidence for the ages and sources of fluid components of gold-bearing quartz veins in the northern Sierra Nevada foothills metamorphic belt, California

    Science.gov (United States)

    Böhlke, John Karl; Kistler, R. W.

    1986-01-01

    Gold-bearing quartz veins occur in and near major fault zones in deformed oceanic and island-arc rocks west of the main outcrop of the Sierra Nevada composite batholith. Veins typically occupy minor reverse faults that crosscut blueschist to amphibolite-grade metamorphic rocks whose metamorphic ages range from early Paleozoic to Jurassic. Vein micas and carbonate-quartz-mica assemblages that formed by hydrothermal metasomatism of ultramafic wall rocks in the Alleghany, Grass Valley, Washington, and Mother Lode districts yield concordant K-Ar and Rb-Sr ages. The dated veins are significantly younger than prograde metamorphism, penetrative deformation, and accretion of their host rocks to the continental margin. New and previously published mineralization ages from 13 localities in the Sierra foothills range from about 140 to 110 m.y. ago, with mean and median between 120 and 115 m.y. The age relations suggest that mineralizing fluids were set in motion by deep magmatic activity related to the resumption of east-dipping subduction along the western margin of North America following the Late Jurassic Nevadan collision event.CO 2 -bearing fluids responsible for metasomatism and much of the vein mica, carbonate, albite, and quartz deposition in several northern mines were isotopically heavy (delta 18 O [asymp] 8-14ppm; delta D between about -10 and -50ppm) and do not resemble seawater, magmatic, or meteoric waters. Metasomatic and vein-filling mica, dolomite, magnesite, and quartz in altered ultramafic rocks generally formed from fluids with similar Sr and O isotope ratios at a given locality. Consistent quartz-mica delta 18 O fractionations (delta 18 O (sub Q-M) = 4.5-4.9ppm) from various localities imply uniform equilibration temperatures, probably between 300 degrees and 350 degrees C. On a local (mine) scale, fluids responsible for both carbonate alteration of mafic and ultramafic wall rocks and albitic alteration of felsic and pelitic rocks had similar Sr isotope

  17. Isotope hydrological investigations in the region of the Schirmacher Oasis (East Antarctica)

    International Nuclear Information System (INIS)

    Kowski, P.; Richter, W.

    1986-01-01

    A first complete view is given about the isotope hydrological situation of the Schirmacher Oasis and surroundings by means of studies of delta Deuterium and delta Oxygen 18 variations. The precipitation is assumed to be condensed in a distance of about 100 km and in a hight of the surface of the inland ice between 1,000 m and 1,500 m a.s.l. in the mean wind direction South East. The deltaD value studies of the shelf and inland ice have shown that both the basal zone of the inland ice and the ice shelf represent relics of an assumed thicker late Pleistocene ice cap of Dronning Maud Land. The main part of the glacier ice is composed of recent local precipitation. The isotope hydrological studies are also a contribution to the characterisation of the high polar fresh-water lakes, ponds and pools under different limnological conditions. (author)

  18. Stable isotopes of hydrogen and oxygen in surface water and ground water at selected sites on or near the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Ott, D.S.; Cecil, L.D.; Knobel, L.L.

    1994-01-01

    Relative stable isotopic ratios for hydrogen and oxygen compared to standard mean ocean water are presented for water from 4 surface-water sites and 38 ground-water sites on or near the Idaho National Engineering Laboratory (INEL). The surface-water samples were collected monthly from March 1991 through April 1992 and after a storm event on June 18, 1992. The ground-water samples either were collected during 1991 or 1992. These data were collected as part of the US Geological Survey's continuing hydrogeological investigations at the INEL. The relative isotopic ratios of hydrogen and oxygen are reported as delta 2 H (δ 2 H) and as delta 18 O (δ 18 O), respectively. The values of δ 2 H and δ 18 O in water from the four surface-water sites ranged from -143.0 to -122 and from -18.75 to -15.55, respectively. The values of δ 2 H and δ 18 O in water from the 38 ground-water sites ranged from -141.0 to -120.0 and from -18.55 to -14.95, respectively

  19. Physical, biogeochemical, and isotopic tracer data collected aboard the FS POLARSTERN during the ARKXXIII/3 expedition in the Arctic Ocean from 24 August 2008 to 05 October 2008 (NODC Accession 0065370)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset includes chemical analyses of dissolved organic carbon, total dissolved nitrogen, nitrate, total alkalinity,delta 18-O, and 228-226-RA collected from...

  20. Human impacts on groundwater flow and contamination deduced by multiple isotopes in Seoul City, South Korea

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Takahiro, E-mail: hosono@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Ikawa, Reo, E-mail: r_ikawa@es.sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Shimada, Jun, E-mail: jshimada@sci.kumamoto-u.ac.jp [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Nakano, Takanori, E-mail: nakanot@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Saito, Mitsuyo, E-mail: misaito@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Onodera, Shin-ichi, E-mail: sonodera@hiroshima-u.ac.jp [Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1, Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521 (Japan); Lee, Kang-Kun, E-mail: kklee@snu.ac.kr [School of Earth and Environmental Science, Seoul National University, San 56-1, Shinrim-dong, Kwanak-gu, Seoul 151-747 (Korea, Republic of); Taniguchi, Makoto, E-mail: makoto@chikyu.ac.jp [Research Institute for Humanity and Nature, 457-4 Motoyama Kamigamo, Kita-ku, Kyoto 603-8047 (Japan)

    2009-04-15

    The influence of human activities on the flow system and contamination of groundwater were investigated in Seoul City, South Korea, one of the largest Asian cities, using a combination of isotopes ({delta}D, T, {delta}{sup 15}N, {delta}{sup 18}O, {delta}{sup 34}S, and {sup 87}Sr/{sup 86}Sr). Eighteen representative groundwater and river water samples, which were collected over a wide area of the city, were compared with previously reported data. The distribution of stable isotopes ({delta}D and {delta}{sup 18}O) with groundwater potential data shows that recharged groundwater from either the surrounding mountainous area as well as the Han River and other surface streams discharged towards the northern-central part of the city, where a subway tunnel pumping station is located. It is suggested from T values (3.3 to 5.8 T.U.) that groundwater was recharged in the last 30 to 40 years. The {delta}{sup 34}S and {delta}{sup 15}N of SO{sub 4}{sup 2-} and NO{sub 3}{sup -} data were efficiently used as indicators of contamination by human activities. These isotopes clarified that the contribution of anthropogenic contaminants i.e., industrial and household effluents, waste landfills, and fertilizers, are responsible for the enrichment by SO{sub 4}{sup 2-} (> 30 ppm as SO{sub 4}{sup 2-}) and NO{sub 3}{sup -} (> 20 ppm as NO{sub 3}{sup -}) of groundwater. The {sup 87}Sr/{sup 86}Sr values of groundwater vary (0.71326 to 0.75058) in accordance with the host rocks of different origins. Mineral elements such as Ca are also suggested to be derived naturally from rocks. The groundwater under Seoul City is greatly affected by transportation of pollutants along the groundwater flow controlled by subway tunnel pumping, contributing to the degradation of water quality in urbanized areas.

  1. Karst springs as 'natural' pluviometers: Constraints on the isotopic composition of rainfall in the Apennines of central Italy

    Energy Technology Data Exchange (ETDEWEB)

    Minissale, A., E-mail: minissa@igg.cnr.it [CNR - Italian Council for Research, Institute of Geosciences and Earth Resources (Section of Florence) - Via La Pira 4, 50121 Firenze (Italy); Vaselli, O. [CNR - Italian Council for Research, Institute of Geosciences and Earth Resources (Section of Florence) - Via La Pira 4, 50121 Firenze (Italy)] [Department of Earth Sciences, University of Florence - Via La Pira 4, 50121 Firenze (Italy)

    2011-05-15

    Highlights: > Isotopic compositions of karstic springs in central Italy have been reviewed. > Isotopic gradients of rainfalls for elevations have been evaluated in an Alpine valley. > Karstic drops have been calculated by using isotopic compositions of springs. > Isotopic compositions of rainfalls in central Italy have been re-calculated using the isotopic compositions of karstic springs. - Abstract: This paper describes an indirect method to calculate the isotopic composition of rainfall by using the isotopic composition of karst springs fed by waters circulating in the most important regional aquifer of central Italy, i.e. the Mesozoic limestone sequence that forms the backbone of the Apennines. By using {delta}{sup 18}O and {delta}D data and the {delta}{sup 18}O (and/or {delta}D) average gradient for elevation, evaluated through the use of literature rainfall data and new measurements from a typical Alpine valley in northern Italy, the altitude of precipitation of their parent water has been re-calculated. Vertical descents of more than 2000 m, from recharge to discharge, have been assessed in some high flow-rate cold springs in the morphologically steep Adriatic sector of central Italy. A clear correlation between the vertical descents and more negative isotopic compositions at their relative emergence elevations is highlighted. In contrast, in the Tyrrhenian sector lower karstic drops (generally lower than 500 m) correlate with less negative isotopic composition of recharge areas. The {delta}{sup 18}O iso-contour map of the 'recalculated' parent rainfall in central Italy is more detailed than any possible isotopic map of rainfall made using pluviometers, unless large number of rainfall collectors were deployed on mountaintops. The data also show that the isotopic composition of rainfall depends on the source of the storm water. In particular, precipitation is isotopically heavier when originating in the Mediterranean Sea, and lighter when formed in

  2. Novel silver tubing method for quantitative introduction of water into high temperature conversion systems for stable hydrogen and oxygen isotopic measurements

    Science.gov (United States)

    Qi, Haiping; Groning, Manfred; Coplen, Tyler B.; Buck, Bryan; Mroczkowski, Stanley J.; Brand, Willi A.; Geilmann, Heike; Gehre, Matthias

    2010-01-01

    A new method to seal water in silver tubes for use in a TC/EA reduction unit using a semi-automated sealing apparatus can yield reproducibilities (1 standard deviation) of δ2H and &delta18O measurements of 1.0 ‰ and 0.06 ‰, respectively. These silver tubes containing reference waters may be preferred for calibration of H- and O-bearing materials analyzed with a TC/EA reduction unit. The new sealing apparatus employs a computer controlled stepping motor to produce silver tubes identical in length. The reproducibility of mass of water sealed in tubes (in a range of 200 to 400 µg) can be as good as 1 percent. Although silver tubes sealed with reference waters are robust and can be shaken or heated to 110 °C with no loss of integrity, they should not be frozen because the expansion during the phase transition of water to ice will break the cold seals and all water will be lost. They should be shipped in insulated containers. This new method eliminates air inclusions and isotopic fractionation of water associated with the loading of water into capsules using a syringe. The method is also more than an order of magnitude faster than preparing water samples in ordinary Ag capsules. Nevertheless, some laboratories may prefer loading water into silver capsules because expensive equipment is not needed, but they are cautioned to apply the necessary corrections for evaporation, back exchange with laboratory atmospheric moisture, and blank.

  3. Stable Isotope (delta OXYGEN-18, Delta Deuterium, Delta CARBON-13) Dendroclimatological Studies in the Waterloo Region of Southern Ontario, Canada, Between AD 1610 and 1990.

    Science.gov (United States)

    Buhay, William Mark

    Oxygen (delta^{18} O), hydrogen (delta^2H) and carbon (delta^{13}C) isotopes were measured in wood cellulose from elm, white pine and maple trees that grew in southwestern Ontario, Canada. The measured oxygen and hydrogen isotopic data were used for model-based reconstructions of delta^{18}{O}_{meteoric water}, mean annual temperature (MAT) and relative humidity for a period, AD 1610 to 1880, that precedes instrumental records of climate. The carbon isotope measurements were compared with the Cellulose Model inferred climate data to reveal additional environmental information. Modifications made to the Cellulose Model focused on the dynamics of oxygen and hydrogen isotopic fractionation in plants during evapotranspiration and photosynthetic assimilation. For instance, kinetic fractionation of ^{18}O was found to be predictable from theoretical considerations of leaf energy balance and boundary layer dynamics. Kinetic fractionation during evapotranspiration is sensitive to the nature of the boundary layer, which is controlled by leaf size and morphology. Generally, plants with small segmented leaves have a lower component of turbidity in the leaf boundary layer, which results in higher kinetic fractionation values, than do plants having large simple leaves and more turbulent boundary layers. Kinetic ^2H enrichment in plant leaf water can also be rationalized in terms of leaf size and morphology when an apparent temperature-dependent isotope effect, acting in opposition to evaporative enrichment, is taken into account. Accounting for this temperature -dependent isotope effect helps to: (1) reconcile hydrogen kinetic fractionation inconsistencies for different leaves; (2) explain a temperature effect previously attributed to variable biochemical fractionation during cellulose synthesis, and; (3) verify hydrogen biochemical effects in plants. This improved characterization of the oxygen and hydrogen isotopic effects in plants, using the modified Cellulose Model, helped

  4. Stable isotope geochemistry of deep sea cherts

    Energy Technology Data Exchange (ETDEWEB)

    Kolodny, Y; Epstein, S [California Inst. of Tech., Pasadena (USA). Div. of Geological Sciences

    1976-10-01

    Seventy four samples of DSDP (Deep Sea Drilling Project) recovered cherts of Jurassic to Miocene age from varying locations, and 27 samples of on-land exposed cherts were analyzed for the isotopic composition of their oxygen and hydrogen. These studies were accompanied by mineralogical analyses and some isotopic analyses of the coexisting carbonates. delta/sup 18/0 of chert ranges between 27 and 39 parts per thousand relative to SMOW, delta/sup 18/0 of porcellanite - between 30 and 42 parts per thousand. The consistent enrichment of opal-CT in porcellanites in /sup 18/0 with respect to coexisting microcrystalline quartz in chert is probably a reflection of a different temperature (depth) of diagenesis of the two phases. delta/sup 18/0 of deep sea cherts generally decrease with increasing age, indicating an overall cooling of the ocean bottom during the last 150 m.y. A comparison of this trend with that recorded by benthonic foraminifera (Douglas et al., Initial Reports of the Deep Sea Drilling Project; 32:509(1975)) indicates the possibility of delta/sup 18/0 in deep sea cherts not being frozen in until several tens of millions of years after deposition. Cherts of any Age show a spread of delta/sup 18/0 values, increasing diagenesis being reflected in a lowering of delta/sup 18/0. Drusy quartz has the lowest delta/sup 18/0 values. On land exposed cherts are consistently depleted in /sup 18/0 in comparison to their deep sea time equivalent cherts. Water extracted from deep sea cherts ranges between 0.5 and 1.4 wt%. deltaD of this water ranges between -78 and -95 parts per thousand and is not a function of delta/sup 18/0 of the cherts (or the temperature of their formation).

  5. Oxygen isotopic composition of sulphates from some mineral waters and mine waters in western Bohemia

    International Nuclear Information System (INIS)

    Smejkal, V.

    1979-01-01

    Two main genetic types of sulphate can be distinguished according to the delta 18 O(SO 4 2- ) measurements in sulphate-rich mineral and mine waters of western Bohemia - sulphates in descending mine waters and in weathered outcrops of graphitic pyrite slates from areas outside Tertiary basins, which originated in recent time by the oxidation of sulphides in the presence of atmospheric oxygen, have delta 18 O values from -2.1 to -6.1 per mille SMOW; and sulphates from springs of mineral waters of the renowned spas of Karlovy Vary, Frantiskovy Lazne and Marianske Lazne show distinctly heavier delta 18 O values - from +4.0 to +6.4 per mille, with maximum of values between +5.0 and +6.0 per mille. Similar delta 18 O values have been established in thenardites and in gypsum in Miocene claystones and in sulphates of some mine waters in the nearby Tertiary Cheb and Sokolov Basins. The presented results indicate that sulphates in mineral waters of the Karlovy Vary type originate mainly by leaching of Miocene sulphates and not by present-day oxidation of sulphidic sulphur. (author)

  6. Hydrographic changes in the Agulhas Recirculation Region during the late Quaternary.

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, Dinesh K.; Saraswat, R.; Khare, N.; Pandey, A.C.; Nigam, R.

    glacial–interglacial cycle, here we reconstruct hydrographic changes in the southwestern Indian Ocean from temporal variation in planktic foraminiferal abundance, stable isotopic ratio (delta 18O) and trace elemental ratio (Mg/Ca) of planktic foraminifera...

  7. Isotopic clusters

    International Nuclear Information System (INIS)

    Geraedts, J.M.P.

    1983-01-01

    Spectra of isotopically mixed clusters (dimers of SF 6 ) are calculated as well as transition frequencies. The result leads to speculations about the suitability of the laser-cluster fragmentation process for isotope separation. (Auth.)

  8. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  9. Isotope separation

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1979-01-01

    A method of isotope separation is described which involves the use of a laser photon beam to selectively induce energy level transitions of an isotope molecule containing the isotope to be separated. The use of the technique for 235 U enrichment is demonstrated. (UK)

  10. Carbonate Mineral Formation on Mars: Clues from Stable Isotope Variation Seen in Cryogenic Laboratory Studies of Carbonate Salts

    Science.gov (United States)

    Socki, Richard; Niles, Paul B.; Sun, Tao; Fu, Qi; Romanek, Christopher S.; Gibson, Everett K.

    2013-01-01

    The geologic history of water on the planet Mars is intimately connected to the formation of carbonate minerals through atmospheric CO2 and its control of the climate history of Mars. Carbonate mineral formation under modern martian atmospheric conditions could be a critical factor in controlling the martian climate in a means similar to the rock weathering cycle on Earth. The combination of evidence for liquid water on the martian surface and cold surface conditions suggest fluid freezing could be very common on the surface of Mars. Cryogenic calcite forms readily when a rise in pH occurs as a result of carbon dioxide degassing quickly from freezing Ca-bicarbonate-rich water solutions. This is a process that has been observed in some terrestrial settings such as arctic permafrost cave deposits, lakebeds of the Dry Valleys of Antarctica, and in aufeis (river icings) from rivers of N.E. Alaska. We report here the results of a series of laboratory experiments that were conducted to simulate potential cryogenic carbonate formation on the planet Mars. These results indicate that carbonates grown under martian conditions (controlled atmospheric pressure and temperature) show enrichments from starting bicarbonate fluids in both carbon and oxygen isotopes beyond equilibrium values with average delta13C(DIC-CARB) values of 20.5%0 which exceed the expected equilibrium fractionation factor of [10(sup 3) ln alpha = 13%0] at 0 degC. Oxygen isotopes showed a smaller enrichment with delta18O(H2O-CARB) values of 35.5%0, slightly exceeding the equilibrium fractionation factor of [10(sup 3) ln alpha = 34%0 ] at 0degC. Large kinetic carbon isotope effects during carbonate precipitation could substantially affect the carbon isotope evolution of CO2 on Mars allowing for more efficient removal of 13C from the Noachian atmosphere enriched by atmospheric loss. This mechanism would be consistent with the observations of large carbon isotope variations in martian materials despite the

  11. Changes in the isotopic and chemical composition of ground water resulting from a recharge pulse from a sinking stream

    Science.gov (United States)

    Katz, Brian G.; Catches, John S.; Bullen, Thomas D.; Michel, Robert L.

    1998-11-01

    The Little River, an ephemeral stream that drains a watershed of approximately 88 km 2 in northern Florida, disappears into a series of sinkholes along the Cody Scarp and flows directly into the carbonate Upper Floridan aquifer, the source of water supply in northern Florida. The changes in the geochemistry of ground water caused by a major recharge pulse from the sinking stream were investigated using chemical and isotopic tracers and mass-balance modeling techniques. Nine monitoring wells were installed open to the uppermost part of the aquifer in areas near the sinks where numerous subterranean karst solution features were identified using ground penetrating radar. During high-flow conditions in the Little River, the chemistry of water in some of the monitoring wells changed, reflecting the mixing of river water with ground water. Rapid recharge of river water into some parts of the aquifer during high-flow conditions was indicated by enriched values of delta 18O and delta deuterium (-1.67 to -3.17 per mil and -9.2 to -15.6 per mil, respectively), elevated concentrations of tannic acid, higher (more radiogenic) 87Sr/ 86Sr ratios, and lower concentrations of 222Rn, silica, and alkalinity compared to low-flow conditions. The proportion of river water that mixed with ground water ranged from 0.10 to 0.67 based on binary mixing models using the tracers 18O, deuterium, tannic acid, silica, 222Rn, and 87Sr/ 86Sr. On the basis of mass-balance modeling during steady-state flow conditions, the dominant processes controlling carbon cycling in ground water are the dissolution of calcite and dolomite in aquifer material, and aerobic degradation of organic matter.

  12. Environmental isotope study of groundwater systems in the Republic of Djibouti

    International Nuclear Information System (INIS)

    Fontes, J.Ch.; Saliege, J.F.; Zuppi, G.M.; Pouchan, P.

    1980-01-01

    Environmental isotopes and hydrogeochemistry are being used to shed new light on the occurrence of present-day recharge and on the origin of groundwater systems in the Republic of Djibouti. Furthermore, an attempt is also being made to evaluate palaeohydrological conditions during the past 6000 years. From stable isotope data which lie along a correlation line at a slope of 8 in the diagram delta 2 H-delta 18 O, it can be concluded that recharge occurs by rapid seepage in fractured rocks without evaporation. Some waters from hot springs show an oxygen shift, indicating the occurrence of an exchange process with rocks at high temperatures. The following conclusions can be reached from tritium and 14 C content of waters. Groundwaters can be divided into two groups: one deriving from recent recharge (last five or six years) corresponding to water with rather fast circulations in fractured media; and a second group, pre-bomb recharged corresponding to water with low flow rates in porous media. Only one sample (Yoboki) seems to derive from about 10-year-old recharge. In the case of Abhe hot spring, a 14 C age of about 1200 years may be evaluated. The calcite concretions of the Abhe Lake Basin are believed to have formed as a result of the mixing of lake water (sodium-carbonate type) with groundwater (sodium-chloride, calcium-sulphate type). From the 13 C and 14 C content it appears that the dissolved carbon of present-day lake water is in, or close to, equilibrium with the atmosphere. Consequently, it is assumed that such was also the case during the whole Holocene. The 18 O content of palaeolake water, evaluated from the calcite isotopic composition with the palaeo-temperature equation, was originally more negative than the present one. This is interpreted as due to the fact that the Holocene lake was fed by large floods and that significant seepage occurred through the lake bottom with a consequent reduction of the evaporation effects. (author)

  13. Paired measurements of foraminiferal delta 18 O and Mg/Ca ratios of Indian monsoons reconstructed from Holocene to Last Glacial record

    Digital Repository Service at National Institute of Oceanography (India)

    Mahesh, B.; Banakar, V.K.; Burr, G.

    et al., 1993; Anderson and Prell, 1993; Clemens and Prell, 1990; Prell and Van Campo, 1986; Duplessy, 1982). The robust proxy to monitor monsoon intensity could be the variation in SS as it instantly responds to changes in evaporation- precipitation...

  14. Isotope enrichment

    International Nuclear Information System (INIS)

    Garbuny, M.

    1979-01-01

    The invention discloses a method for deriving, from a starting material including an element having a plurality of isotopes, derived material enriched in one isotope of the element. The starting material is deposited on a substrate at less than a critical submonatomic surface density, typically less than 10 16 atoms per square centimeter. The deposit is then selectively irradiated by a laser (maser or electronic oscillator) beam with monochromatic coherent radiation resonant with the one isotope causing the material including the one istope to escape from the substrate. The escaping enriched material is then collected. Where the element has two isotopes, one of which is to be collected, the deposit may be irradiated with radiation resonant with the other isotope and the residual material enriched in the one isotope may be evaporated from the substrate and collected

  15. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  16. Isotope separation

    International Nuclear Information System (INIS)

    Bartlett, R.J.; Morrey, J.R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated

  17. Isotopic separation

    International Nuclear Information System (INIS)

    Castle, P.M.

    1979-01-01

    This invention relates to molecular and atomic isotope separation and is particularly applicable to the separation of 235 U from other uranium isotopes including 238 U. In the method described a desired isotope is separated mechanically from an atomic or molecular beam formed from an isotope mixture utilising the isotropic recoil momenta resulting from selective excitation of the desired isotope species by radiation, followed by ionization or dissociation by radiation or electron attachment. By forming a matrix of UF 6 molecules in HBr molecules so as to collapse the V 3 vibrational mode of the UF 6 molecule the 235 UF 6 molecules are selectively excited to promote reduction of UF 6 molecules containing 235 U and facilitate separation. (UK)

  18. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1979-01-01

    Isotopic species in an isotopic mixture including a first species having a first isotope and a second species having a second isotope are separated by selectively exciting the first species in preference to the second species and then reacting the selectively excited first species with an additional preselected radiation, an electron or another chemical species so as to form a product having a mass different from the original species and separating the product from the balance of the mixture in a centrifugal separating device such as centrifuge or aerodynamic nozzle. In the centrifuge the isotopic mixture is passed into a rotor where it is irradiated through a window. Heavier and lighter components can be withdrawn. The irradiated mixture experiences a large centrifugal force and is separated in a deflection area into lighter and heavier components. (UK)

  19. Aspects of the isotope hydrology of the Great Artesian Basin, Australia

    International Nuclear Information System (INIS)

    Airey, P.L.; Calf, G.E.; Campbell, B.L.; Hartley, P.E.; Roman, D.

    1979-01-01

    A study has been made of the isotope hydrology of the principal Jurassic aquifer of the Queensland portion of the Great Artesian Basin down-gradient of the recharge area. Much of the data have been interpreted in terms of the residence times of the groundwater samples which were up to 350,000 years. It is postulated that the observed systematic variations in the chloride levels reflect variations in the rate of infiltration of recycled salt throughout the late Quaternary. The minimum and maximum in the chloride curve correlate with the last glacial and interglacial period respectively. The bicarbonate ion levels are perturbed by the dissolution of carbonate minerals. About 0.1% of the aquifer material would have been dissolved since the mid-Tertiary when the present hydrodynamic conditions were established if dissolution rates calculated from the geochemical model are representative. The D/H ratios were found to be extremely constant. The 46 wells sited away from the recharge area have a mean deltaD of -41.8 per mille and a standard deviation of 1.1. There was no isotopic evidence for exchange of oxygen between water and the host rock despite the long contact periods, sometimes at elevated temperatures. A 226 Ra, 238 U survey showed that radium is frequently in excess despite extensive leaching since the Tertiary times and the fact that the time scales associated with the transport of water are large compared with the half life of 226 Ra. (author)

  20. Isotope angiocardiography

    International Nuclear Information System (INIS)

    Stepinska, J.; Ruzyllo, W.; Konieczny, W.

    1979-01-01

    Method of technetium isotope 99 m pass through the heart recording with the aid of radioisotope scanner connected with seriograph and computer is being presented. Preliminary tests were carried out in 26 patients with coronary disease without or with previous myocardial infarction, cardiomyopathy, ventricular septal defect and in patients with artificial mitral and aortic valves. The obtained scans were evaluated qualitatively and compared with performed later contrast X-rays of the heart. Size of the right ventricle, volume and rate of left atrial evacuation, size and contractability of left ventricle were evaluated. Similarity of direct and isotope angiocardiographs, non-invasional character and repeatability of isotope angiocardiography advocate its usefulness. (author)

  1. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  2. Isotope Identification

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-18

    The objective of this training modules is to examine the process of using gamma spectroscopy for radionuclide identification; apply pattern recognition to gamma spectra; identify methods of verifying energy calibration; and discuss potential causes of isotope misidentification.

  3. Isotope laboratories

    International Nuclear Information System (INIS)

    1978-01-01

    This report from the Dutch Ministry of Health is an advisory document concerned with isotope laboratories in hospitals, in connection with the Dutch laws for hospitals. It discusses which hospitals should have isotope laboratories and concludes that as many hospitals as possible should have small laboratories so that emergency cases can be dealt with. It divides the Netherlands into regions and suggests which hospitals should have these facilities. The questions of how big each lab. is to be, what equipment each has, how each lab. is organised, what therapeutic and diagnostic work should be carried out by each, etc. are discussed. The answers are provided by reports from working groups for in vivo diagnostics, in vitro diagnostics, therapy, and safety and their results form the criteria for the licences of isotope labs. The results of a questionnaire for isotope labs. already in the Netherlands are presented, and their activities outlined. (C.F.)

  4. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  5. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1982-01-01

    A method is described for separating isotopes in which photo-excitation of selected isotope species is used together with the reaction of the excited species with postive ions of predetermined ionization energy, other excited species, or free electrons to produce ions or ion fragments of the selected species. Ions and electrons are produced by an electrical discharge, and separation is achieved through radial ambipolar diffusion, electrostatic techniques, or magnetohydrodynamic methods

  6. Isotope enrichment

    International Nuclear Information System (INIS)

    Lydtin, H-J.; Wilden, R.J.; Severin, P.J.W.

    1978-01-01

    The isotope enrichment method described is based on the recognition that, owing to mass diffusion and thermal diffusion in the conversion of substances at a heated substrate while depositing an element or compound onto the substrate, enrichment of the element, or a compound of the element, with a lighter isotope will occur. The cycle is repeated for as many times as is necessary to obtain the degree of enrichment required

  7. Isotopic Evolution of Wells in the Geothermal Field of Los Azufres, Michoacan, Mexico; Evolucion isotopica de fluidos de pozos del campo geotermico de Los Azufres, Michoacan, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Barragan Reyes, Rosa Maria; Portugal Marin, Enrique; Arellano Gomez, Victor Manel; Aragon Aguilar, Alfonso [Instituto de Investigaciones Electricas (Mexico); Sandoval Medina, Fernando [Comision Federal de Electricidad (Mexico)

    2002-12-01

    Isotopic ({delta}{sup 1}8 O and {delta}D) data from production and reinjection web fluids from the Los Azufres geothermal field were interpreted in order to define reservoir evolution and the occurrence of physical processes as a result of exploitation. The study included data of 30 wells, which were sampled in September, 2000. General results indicate that different phenomena seem to occur in both zones of the field. In the southern zone there are two different trends of behavior: a mixture of fluids evidenced by the {delta}D versus {delta}{sup 1}8 O trend with a positive slope, was interpreted as the result of reservoir vapor separation at a temperature above 220 Celsius degrees, since for temperatures above 220 Celsius degrees deuterium behaves as a volatile component. No well-defined {delta}{sup D} vs {delta}{sup 1}8 O trend was found for the northern zone, but some points seem to fit the same negative slope trend found in the souther zone. The study of reservoir temperatures estimated by different approaches for particular wells through time, as well as temperature results obtained with a heat and flow well simulator, suggest that reservoir boiling occurs in localized areas in both zone of the field. This process is probably due to exploitation. [Spanish] Se interpretaron datos isotopicos ({delta}{sup 1}8 O y {delta}D) de fluidos de pozos productores y de reinyeccion del campo geotermico de Los Azufres, Michoacan, Mexico, para definir la evolucion del yacimiento y la ocurrencia de procesos fisicos como resultado de la explotacion. En el estudio se consideran datos de treinta pozos segun el muestreo realizado en septiembre de 2000. El estudio de la evolucion en el tiempo de las estimaciones de temperatura de yacimiento mediante diferentes tecnicas, asi como la temperatura obtenida de simulacion de pozos, sugiere que ocurre ebullicion en areas localizadas en ambas zonas del campo debido a la explotacion. Los resultados generales indican la existencia de

  8. Isotopes Project

    International Nuclear Information System (INIS)

    Dairiki, J.M.; Browne, E.; Firestone, R.B.; Lederer, C.M.; Shirley, V.S.

    1984-01-01

    The Isotopes Project compiles and evaluates nuclear structure and decay data and disseminates these data to the scientific community. From 1940-1978 the Project had as its main objective the production of the Table of Isotopes. Since publication of the seventh (and last) edition in 1978, the group now coordinates its nuclear data evaluation efforts with those of other data centers via national and international nuclear data networks. The group is currently responsible for the evaluation of mass chains A = 167-194. All evaluated data are entered into the International Evaluated Nuclear Structure Data File (ENSDF) and are published in Nuclear Data Sheets. In addition to the evaluation effort, the Isotopes Project is responsible for production of the Radioactivity Handbook

  9. Isotope production

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Dewi M.

    1995-07-15

    Some 2 0% of patients using radiopharmaceuticals receive injections of materials produced by cyclotrons. There are over 200 cyclotrons worldwide; around 35 are operated by commercial companies solely for the production of radio-pharmaceuticals with another 25 accelerators producing medically useful isotopes. These neutron-deficient isotopes are usually produced by proton bombardment. All commonly used medical isotopes can be generated by 'compact' cyclotrons with energies up to 40 MeV and beam intensities in the range 50 to 400 microamps. Specially designed target systems contain gram-quantities of highly enriched stable isotopes as starting materials. The targets can accommodate the high power densities of the proton beams and are designed for automated remote handling. The complete manufacturing cycle includes large-scale target production, isotope generation by cyclotron beam bombardment, radio-chemical extraction, pharmaceutical dispensing, raw material recovery, and labelling/packaging prior to the rapid delivery of these short-lived products. All these manufacturing steps adhere to the pharmaceutical industry standards of Good Manufacturing Practice (GMP). Unlike research accelerators, commercial cyclotrons are customized 'compact' machines usually supplied by specialist companies such as IBA (Belgium), EBCO (Canada) or Scanditronix (Sweden). The design criteria for these commercial cyclotrons are - small magnet dimensions, power-efficient operation of magnet and radiofrequency systems, high intensity extracted proton beams, well defined beam size and automated computer control. Performance requirements include rapid startup and shutdown, high reliability to support the daily production of short-lived isotopes and low maintenance to minimize the radiation dose to personnel. In 1987 a major step forward in meeting these exacting industrial requirements came when IBA, together with the University of Louvain-La-Neuve in Belgium, developed the Cyclone-30

  10. Reconstructing Hydrologic Variability in Southwestern North America Using Speleothem Proxies and Precipitation Isotopes from California

    Science.gov (United States)

    McCabe-Glynn, Staryl

    Precipitation in southwestern North America has exhibited significant natural variability over the past few thousand years. This variability has been attributed to sea surface temperature regimes in the Pacific and Atlantic oceans, and to the attendant shifts in atmospheric circulation patterns. In particular, decadal variability in the North Pacific has influenced precipitation in this region during the twentieth century, but links to earlier droughts and pluvials are unclear. Here I assess these links using delta18 O measurements from a speleothem from southern California that spans AD 854-- 2007. I show that variations in the oxygen isotopes of the speleothem correlate to sea surface temperatures in the Kuroshio Extension region of the North Pacific, which affect the atmospheric trajectory and isotopic composition of moisture reaching the study site. Interpreting our speleothem data as a record of sea surface temperatures in the Kuroshio Extension, I find a strong 22-year periodicity, suggesting a persistent solar influence on North Pacific decadal variability. A comparison with tree-ring records of precipitation during the past millennium shows that some droughts occurred during periods of warmth in the Kuroshio Extension, similar to the instrumental record. However, other droughts did not and instead were likely influenced by other factors. The carbon isotope record indicates drier conditions are associated with higher delta13C values and may be a suitable proxy for reconstructing past drought variability. More research is needed to determine the controls on trace element concentrations. Finally, I find a significant increase in sea surface temperature variability over the past 150 years, which may reflect an influence of greenhouse gas concentrations on variability in the North Pacific. While drought is a common feature of climate in this region, most climate models also project extreme precipitation events to increase in frequency and severity because the

  11. Isotopically modified compounds

    International Nuclear Information System (INIS)

    Kuruc, J.

    2009-01-01

    In this chapter the nomenclature of isotopically modified compounds in Slovak language is described. This chapter consists of following parts: (1) Isotopically substituted compounds; (2) Specifically isotopically labelled compounds; (3) Selectively isotopically labelled compounds; (4) Non-selectively isotopically labelled compounds; (5) Isotopically deficient compounds.

  12. Isotope generator

    International Nuclear Information System (INIS)

    1979-01-01

    The patent describes an isotope generator incorporating the possibility of stopping elution before the elution vessel is completely full. Sterile ventilation of the whole system can then occur, including of both generator reservoir and elution vessel. A sterile, and therefore pharmaceutically acceptable, elution fluid is thus obtained and the interior of the generator is not polluted with non-sterile air. (T.P.)

  13. Isotope hydrology

    International Nuclear Information System (INIS)

    Drost, W.

    1978-01-01

    The International Symposium on Isotope Hydrology was jointly organized by the IAEA and UNESCO, in co-operation with the National Committee of the Federal Republic of Germany for the International Hydrological Programme (IHP) and the Gesellschaft fuer Strahlen- und Umweltforschung mbH (GSF). Upon the invitation of the Federal Republic of Germany the Symposium was held from 19-23 June 1978 in Neuherberg on the GSF campus. The Symposium was officially opened by Mr. S. Eklund, Director General of the IAEA. The symposium - the fifth meeting held on isotope hydrology - was attended by over 160 participants from 44 countries and four international organizations and by about 30 observers from the Federal Republic of Germany. Due to the absence of scientists from the USSR five papers were cancelled and therefore only 46 papers of the original programme were presented in ten sessions

  14. Time-series analysis of ion and isotope geochemistry of selected springs of the Nevada Test Site, Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Lyles, B.F.; Edkins, J.; Jacobson, R.L.; Hess, J.W.

    1990-11-01

    The temporal variations of ion and isotope geochemistry were observed at six selected springs on the Nevada Test Site, Nye County, Nevada and included: Cane, Whiterock, Captain Jack, Topopah, Tippipah, and Oak Springs. The sites were monitored from 1980 to 1982 and the following parameters were measured: temperature, pH, electrical conductance, discharge, cations (Ca{sup 2+}, Mg{sup 2+}. Na{sup +}, K{sup +}), anions Cl{sup {minus}}, SO{sub 4}{sup 2{minus}}. HCO{sub 3}{sup {minus}}, silica, stable isotopes ({delta}{sup 18}O, {delta}D, {delta}{sup 13}C), and radioactive isotopes ({sup 3}H, {sup 14}C). A more detailed study was continued from 1982 to 1988 at Cane and Whiterock Springs. Field microloggers were installed at these sites in 1985 to measure the high frequency response of temperature, electrical conductance, and discharge to local precipitation. Stage fluctuations near the discharge point dissolve minerals/salts as groundwater inundates the mineralized zone immediately above the equilibrium water table. This phenomena was most noticeable at Whiterock Spring and lagged the discharge response by several hours. Stable isotope analysis of precipitation and groundwater suggests a 1.5 to 2 month travel time for meteoric water to migrate from the recharge area to the discharge point. Groundwater age determinations suggest a mean age of approximately 30 years at Whiterock Spring and possibly older at Cane Spring. However, the short travel time and geochemical integrity of recharge pulses suggest that the waters are poorly mixed along the flow paths. 25 refs., 25 figs., 24 tabs.

  15. Natural isotopes

    International Nuclear Information System (INIS)

    Vogel, J.C.

    1986-01-01

    14 C dates between 600 and 900 AD were obtained for early Iron Age sites in Natal, and from 1300 to 1450 AD for rock engraving sites in Bushmanland. Palaeoenvironmental data derived from the dating of samples related to sedimentary and geomorphic features in the central and northern Namib Desert enabled the production of a tentative graph for the changes in humidity in the region over the past 40000 years. These results suggest that relatively humid conditions came to an end in the Namib at ±25000 BP (before present). The increased precision of the SIRA mass spectrometer enabled the remeasurement of 13 C and 18 O in the Cango stalagmite. This data confirmed that the environmental temperatures in the Southern Cape remained constant to within ±1 o C during the past 5500 years. Techniques and applications for environmental isotopes in hydrology were developed to determine the origin and movement of ground water. Isotopic fractionation effects in light elements in nature were investigated. The 15 N/ 14 N ratio in bones of animals and humans increases in proportion to the aridity of the environment. This suggests that 15 N in bone from dated archaeological sites could be used to detect changes in past climatic conditions as naturally formed nitrate minerals are higly soluble and are only preserved in special, very dry environments. The sources and sinks of CO 2 on the South African subcontinent were also determined. The 13 C/ 12 C ratios of air CO 2 obtained suggest that the vegetation provides the major proportion of respired CO 2 . 9 refs., 1 fig

  16. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  17. Method for separating isotopes

    International Nuclear Information System (INIS)

    Jepson, B.E.

    1975-01-01

    Isotopes are separated by contacting a feed solution containing the isotopes with a cyclic polyether wherein a complex of one isotope is formed with the cyclic polyether, the cyclic polyether complex is extracted from the feed solution, and the isotope is thereafter separated from the cyclic polyether

  18. Method for separating isotopes

    International Nuclear Information System (INIS)

    Jepson, B.E.

    1976-01-01

    The invention comprises a method for separating different isotopes of elements from each other by contacting a feed solution containing the different isotopes with a macrocyclic polyether to preferentially form a macrocyclic polyether complex with the lighter of the different isotopes. The macrocyclic polyether complex is then separated from the lighter isotope depleted feed solution. A chemical separation of isotopes is carried out in which a constant refluxing system permits a continuous countercurrent liquid-liquid extraction. (LL)

  19. Method for separating isotopes

    International Nuclear Information System (INIS)

    Schlenker, R.F.

    1978-01-01

    A vortex tube for separating isotopes is described. A gas mixture containing the isotopic molecules enters the vortex tube under pressure and is separated into a hot discharge flow stream and a cold discharge flow stream. The hot discharge is enriched in lighter isotopic molecules whereas the cold discharge flow stream is enriched in the heavier isotopic molecules. The vortex tube can be used in a single stage or multistage isotope separation apparatus

  20. Isotopic Anomalies in Organic Nanoglobules from Comet 81P/Wild 2: Comparison to Murchison Nanoglobules and Isotopic Anomalies Induced in Terrestrial Organics by Electron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    De Gregorio, B.; Stroud, R; Nittler, L; Alexander, C; Kilcoyne, A; Zega, T

    2010-01-01

    Nanoglobules are a form of organic matter found in interplanetary dust particles and primitive meteorites and are commonly associated with {sup 15}N and D isotopic anomalies that are suggestive of interstellar processes. We report the discovery of two isotopically-anomalous organic globules from the Stardust collection of particles from Comet 81P/Wild 2 and compare them with nanoglobules from the Murchison CM2 meteorite. One globule from Stardust Cometary Track 80 contains highly aromatic organic matter and a large {sup 15}N anomaly ({delta}{sup 15}N = 1120{per_thousand}). Associated, non-globular, organic matter from this track is less enriched in {sup 15}N and contains a mixture of aromatic and oxidized carbon similar to bulk insoluble organic material (IOM) from primitive meteorites. The second globule, from Cometary Track 2, contains non-aromatic organic matter with abundant nitrile ({single_bond}C{triple_bond}N) and carboxyl ({single_bond}COOH) functional groups. It is significantly enriched in D ({delta}D = 1000{per_thousand}) but has a terrestrial {sup 15}N/{sup 14}N ratio. Experiments indicate that similar D enrichments, unaccompanied by {sup 15}N fractionation, can be reproduced in the laboratory by electron irradiation of epoxy or cyanoacrylate. Thus, a terrestrial origin for this globule cannot be ruled out, and, conversely, exposure to high-energy electron irradiation in space may be an important factor in producing D anomalies in organic materials. For comparison, we report two Murchison globules: one with a large {sup 15}N enrichment and highly aromatic chemistry analogous to the Track 80 globule and the other only moderately enriched in {sup 15}N with IOM-like chemistry. The observation of organic globules in Comet 81P/Wild 2 indicates that comets likely sampled the same reservoirs of organic matter as did the chondrite parent bodies. The observed isotopic anomalies in the globules are most likely preserved signatures of low temperature (<10 K

  1. Isotope puzzle in sputtering

    International Nuclear Information System (INIS)

    Zheng Liping

    1998-01-01

    Mechanisms affecting multicomponent material sputtering are complex. Isotope sputtering is the simplest in the multicomponent materials sputtering. Although only mass effect plays a dominant role in the isotope sputtering, there is still an isotope puzzle in sputtering by ion bombardment. The major arguments are as follows: (1) At the zero fluence, is the isotope enrichment ejection-angle-independent or ejection-angle-dependent? (2) Is the isotope angular effect the primary or the secondary sputter effect? (3) How to understand the action of momentum asymmetry in collision cascade on the isotope sputtering?

  2. Implications of ground water chemistry and flow patterns for earthquake studies.

    Science.gov (United States)

    Guangcai, Wang; Zuochen, Zhang; Min, Wang; Cravotta, Charles A; Chenglong, Liu

    2005-01-01

    Ground water can facilitate earthquake development and respond physically and chemically to tectonism. Thus, an understanding of ground water circulation in seismically active regions is important for earthquake prediction. To investigate the roles of ground water in the development and prediction of earthquakes, geological and hydrogeological monitoring was conducted in a seismogenic area in the Yanhuai Basin, China. This study used isotopic and hydrogeochemical methods to characterize ground water samples from six hot springs and two cold springs. The hydrochemical data and associated geological and geophysical data were used to identify possible relations between ground water circulation and seismically active structural features. The data for delta18O, deltaD, tritium, and 14C indicate ground water from hot springs is of meteoric origin with subsurface residence times of 50 to 30,320 years. The reservoir temperature and circulation depths of the hot ground water are 57 degrees C to 160 degrees C and 1600 to 5000 m, respectively, as estimated by quartz and chalcedony geothermometers and the geothermal gradient. Various possible origins of noble gases dissolved in the ground water also were evaluated, indicating mantle and deep crust sources consistent with tectonically active segments. A hard intercalated stratum, where small to moderate earthquakes frequently originate, is present between a deep (10 to 20 km), high-electrical conductivity layer and the zone of active ground water circulation. The ground water anomalies are closely related to the structural peculiarity of each monitoring point. These results could have implications for ground water and seismic studies in other seismogenic areas.

  3. Isotopically exchangeable phosphorus

    International Nuclear Information System (INIS)

    Barbaro, N.O.

    1984-01-01

    A critique revision of isotope dilution is presented. The concepts and use of exchangeable phosphorus, the phosphate adsorption, the kinetics of isotopic exchange and the equilibrium time in soils are discussed. (M.A.C.) [pt

  4. Standardization for oxygen isotope ratio measurement - still an unsolved problem.

    Science.gov (United States)

    Kornexl; Werner; Gehre

    1999-07-01

    Numerous organic and inorganic laboratory standards were gathered from nine European and North American laboratories and were analyzed for their delta(18)O values with a new on-line high temperature pyrolysis system that was calibrated using Vienna standard mean ocean water (VSMOW) and standard light Antartic precipitation (SLAP) internationally distributed reference water samples. Especially for organic materials, discrepancies between reported and measured values were high, ranging up to 2 per thousand. The reasons for these discrepancies are discussed and the need for an exact and reliable calibration of existing reference materials, as well as for the establishment of additional organic and inorganic reference materials is stressed. Copyright 1999 John Wiley & Sons, Ltd.

  5. Optical isotope shifts for unstable samarium isotopes

    International Nuclear Information System (INIS)

    Eastham, D.A.; Walker, P.M.; Griffith, J.A.R.; Evans, D.E.; Grant, I.S.; England, J.G.; Fawcett, M.J.

    1984-01-01

    Using a tunable dye laser beam intersecting a thermal atomic beam, optical isotope shifts and hyperfine splittings have been measured for the four unstable samarium isotopes between 144 Sm and 154 Sm, covering the well known transition region from spherical to deformed shapes. (orig.)

  6. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  7. Geochemistry of silicon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Tiping; Li, Yanhe; Gao, Jianfei; Hu, Bin [Chinese Academy of Geological Science, Beijing (China). Inst. of Mineral Resources; Jiang, Shaoyong [China Univ. of Geosciences, Wuhan (China).

    2018-04-01

    Silicon is one of the most abundant elements in the Earth and silicon isotope geochemistry is important in identifying the silicon source for various geological bodies and in studying the behavior of silicon in different geological processes. This book starts with an introduction on the development of silicon isotope geochemistry. Various analytical methods are described and compared with each other in detail. The mechanisms of silicon isotope fractionation are discussed, and silicon isotope distributions in various extraterrestrial and terrestrial reservoirs are updated. Besides, the applications of silicon isotopes in several important fields are presented.

  8. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  9. Isotope study on the Keuper sandstone aquifer with a leaky cover layer

    International Nuclear Information System (INIS)

    Geyh, M.A.; Backhaus, G.; Andres, G.; Rudolph, J.; Rath, H.K.

    1984-01-01

    Analyses of 14 C, 3 H, 39 Ar, delta 13 C and delta 18 O were performed on groundwater samples taken from the confined Keuper sandstone aquifer north of Nuremberg. The conventional 14 C data apparently contradict the hydrodynamic concept that the age of the deep groundwater flowing from east to west increases in the same direction. A two-dimensional dispersion model is used to convert the conventional 14 C groundwater ages to the regionally valid hydraulic conductivity coefficient of the leaky cover layer confining the aquifer. The basic assumption is that the deep groundwater has a water component which has percolated through the cover layer and which, on mixing, has changed the 14 C ages of the deep groundwater. Therefore, the ratio of the water from 'leaky' recharge to the water from the catchment area plays an important role. Values of delta 18 O and recharge temperatures derived from the noble-gas content of the deep water indicate mixing of Holocene and Pleistocene groundwaters and confirm the model. The considerable differences between the 39 Ar and 14 C groundwater ages may be plausibly explained by the hydrodynamic situation if 39 Ar production in the aquitard is assumed. (author)

  10. Process for isotope separation

    International Nuclear Information System (INIS)

    Emile, B.F.M.

    1983-11-01

    A process is claimed for isotopic separation applied to isotopes of elements that can be placed in at least a physicochemical form in which the isotopic atoms or the molecules containing these atoms can be easily displaced and for which there are selective radiations preferentially absorbed by the isotopes of a certain type or by the molecules containing them, said absorption substantially increasing the probability of ionization of said atoms or molecules relative to the atoms or molecules that did not absorb the radiation. The process consists of placing the isotopic mixture in such a form, subjecting it in a separation zone to selective radiations and to an electrical field that produces migration of positive ions toward the negative electrodes and negative ions toward the positive electrodes, and withdrawing from certain such zones the fractions thus enriched in certain isotopes

  11. Isotopic marking and tracers

    International Nuclear Information System (INIS)

    Morel, F.

    1997-01-01

    The use of radioactive isotopes as tracers in biology has been developed thanks to the economic generation of the required isotopes in accelerators and nuclear reactors, and to the multiple applications of tracers in the life domain; the most usual isotopes employed in biology are carbon, hydrogen, phosphorus and sulfur isotopes, because these elements are present in most of organic molecules. Most of the life science knowledge appears to be dependent to the extensive use of nuclear tools and radioactive tracers; the example of the utilization of radioactive phosphorus marked ATP to study the multiple reactions with proteins, nucleic acids, etc., is given

  12. Isotopes in oxidation reactions

    International Nuclear Information System (INIS)

    Stewart, R.

    1976-01-01

    The use of isotopes in the study of organic oxidation mechanisms is discussed. The help provided by tracer studies to demonstrate the two-equivalent path - hydride transfer, is illustrated by the examples of carbonium oxidants and the Wacker reaction. The role of kinetic isotope effects in the study of the scission of carbon-hydrogen bonds is illustrated by hydride abstraction, hydrogen atom abstraction, proton abstraction and quantum mechanical tunnelling. Isotopic studies on the oxidation of alcohols, carbonyl compounds, amines and hydrocarbons are discussed. The role of isotopes in the study of biochemical oxidation is illustrated with a discussion on nicotinamide and flavin coenzymes. (B.R.H.)

  13. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1976-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. In one embodiment, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by selective dissociation of said excited molecules by the absorption of a single photon of visible or ultraviolet light. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 11 Claims, 2 Drawing Figures

  14. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  15. Discovery of the iron isotopes

    International Nuclear Information System (INIS)

    Schuh, A.; Fritsch, A.; Heim, M.; Shore, A.; Thoennessen, M.

    2010-01-01

    Twenty-eight iron isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  16. Discovery of the silver isotopes

    International Nuclear Information System (INIS)

    Schuh, A.; Fritsch, A.; Ginepro, J.Q.; Heim, M.; Shore, A.; Thoennessen, M.

    2010-01-01

    Thirty-eight silver isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  17. Discovery of the cadmium isotopes

    International Nuclear Information System (INIS)

    Amos, S.; Thoennessen, M.

    2010-01-01

    Thirty-seven cadmium isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  18. Pyrolysis compound specific isotopic analysis (δ13C and δD Py-CSIA) of soil organic matter size fractions under four vegetation covers.

    Science.gov (United States)

    Jiménez-Morillo, Nicasio T.; González-Vila, Francisco J.; Almendros, Gonzalo; De la Rosa, José M.; González-Pérez, José A.

    2015-04-01

    mediated chemical conversions, additions and selective preservation of refractory chemical structures. SOM bulk IRMS and Py-CSIA are also informative about relevant plant physiological processes, OM sources and OM evolution status. Acknowledgments: N.T Jiménez-Morillo is funded by a FPI research grant (BES-2013-062573). Dr. J.M. de la Rosa is the recipient of a fellowship from the JAE-Doc subprogram financed by the CSIC and the European Social Fund. The GEOFIRE Project (CGL2012-38655-C04-01), funded by the Spanish Ministry for Economy and Competitiveness is also acknowledged. Chikaraishi Y, Naraoka H. 2001. Organic hydrogen-carbon isotope signatures of terrestrial higher plants during biosynthesis for distinctive photosynthesis pathways. Geochemical Journal 35: 451-458. Jiménez-Morillo NT, González-Vila FJ, Jordán A, Zavala LM, De la Rosa JM, González-Pérez JA. 2015. Speciation of organic matter in sandy soil size fractions as revealed by analytical pyrolysis (Py-GC/MS) and FT-IR spectroscopy. Geophysical Research Abstracts 17, EGU2015-435. Kendall C, Silva SR, Chang CCY, Burns DA, Campbell DH, Shanley JB. 1996. Use of the Delta 18-O and Delta 15-N of nitrate to determine sources of nitrate in early spring runoff in forested catchments, Isotopes in Water Resources Management. International Atomic Energy Agency symposium, v. 1, pp. 167-176. Leaney FW, Osmond CB, Allison GB, Ziegler H. 1985. Hydrogen-isotope composition of leaf water in C3 and C4 plants: its relationship to the hydrogen-isotope composition of dry matter. Planta Vol164, 2: 215-220. Smith, BN, Epstein S. 1970. Biogeochemistry of the stable isotopes of hydrogen and carbon in salt marsh biota. Plant Physiol. 46: 738-742.

  19. Isotopic research in Antarctica

    International Nuclear Information System (INIS)

    Schuetze, H.

    1983-01-01

    Since 1978 scientists of the Central Institute of Isotope- and Radiation Research of the Academy of Sciences of the GDR have participated in antarctic research. Substantial results have been achieved in research on isotope ratios, on the dynamics of water resources, on concentration of deuterium in lichens, and on age determination of a mummified seal and a penguin colony

  20. Uses of stable isotopes

    International Nuclear Information System (INIS)

    Axente, Damian

    1998-01-01

    The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

  1. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1985-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs

  2. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  3. ICT: isotope correction toolbox.

    Science.gov (United States)

    Jungreuthmayer, Christian; Neubauer, Stefan; Mairinger, Teresa; Zanghellini, Jürgen; Hann, Stephan

    2016-01-01

    Isotope tracer experiments are an invaluable technique to analyze and study the metabolism of biological systems. However, isotope labeling experiments are often affected by naturally abundant isotopes especially in cases where mass spectrometric methods make use of derivatization. The correction of these additive interferences--in particular for complex isotopic systems--is numerically challenging and still an emerging field of research. When positional information is generated via collision-induced dissociation, even more complex calculations for isotopic interference correction are necessary. So far, no freely available tools can handle tandem mass spectrometry data. We present isotope correction toolbox, a program that corrects tandem mass isotopomer data from tandem mass spectrometry experiments. Isotope correction toolbox is written in the multi-platform programming language Perl and, therefore, can be used on all commonly available computer platforms. Source code and documentation can be freely obtained under the Artistic License or the GNU General Public License from: https://github.com/jungreuc/isotope_correction_toolbox/ {christian.jungreuthmayer@boku.ac.at,juergen.zanghellini@boku.ac.at} Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1980-01-01

    Methods and apparatus are disclosed for separation of uranium isotopes by selective isotopic excitation of photochemically reactive uranyl salt source material at cryogenic temperatures, followed by chemical separation of selectively photochemically reduced U+4 thereby produced from remaining uranyl source material

  5. Isotope research materials

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    Preparation of research isotope materials is described. Topics covered include: separation of tritium from aqueous effluents by bipolar electrolysis; stable isotope targets and research materials; radioisotope targets and research materials; preparation of an 241 Am metallurgical specimen; reactor dosimeters; ceramic and cermet development; fission-fragment-generating targets of 235 UO 2 ; and wire dosimeters for Westinghouse--Bettis

  6. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1979-01-01

    A method is described for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption after which more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  7. Superdeformation in Pb isotopes

    International Nuclear Information System (INIS)

    Naz, Tabassum; Ahmad, Shakeb

    2017-01-01

    The Relatvistic Hartree-Bogoliubov (RHB) theory is used to explore the structure of superdeformed (SD) 190,212 Pb isotopes using the non-linear NL3* and density dependent (DD-ME2, DD-PC1) interactions. We have studied the the excitation energy, the potential depth and the deformation of these Pb isotopes

  8. Detecting isotopic ratio outliers

    Science.gov (United States)

    Bayne, C. K.; Smith, D. H.

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers.

  9. Detecting isotopic ratio outliers

    International Nuclear Information System (INIS)

    Bayne, C.K.; Smith, D.H.

    1986-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers

  10. Isotope dilution analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fudge, A.

    1978-12-15

    The following aspects of isotope dilution analysis are covered in this report: fundamental aspects of the technique; elements of interest in the nuclear field, choice and standardization of spike nuclide; pre-treatment to achieve isotopic exchange and chemical separation; sensitivity; selectivity; and accuracy.

  11. Wide angle isotope separator

    International Nuclear Information System (INIS)

    Kantrowitz, A.

    1976-01-01

    A method and apparatus is described for particle separation. The method uses a wide angle radially expanding vapor of a particle mixture. In particular, selective ionization of one isotope type in the particle mixture is produced in a multichamber separator and the ionized isotope type is accelerated out of the path of the vapor expansion for separate collection

  12. Environmental isotope hydrology

    International Nuclear Information System (INIS)

    1973-01-01

    Environmental isotope hydrology is a relatively new field of investigation based on isotopic variations observed in natural waters. These isotopic characteristics have been established over a broad space and time scale. They cannot be controlled by man, but can be observed and interpreted to gain valuable regional information on the origin, turnover and transit time of water in the system which often cannot be obtained by other techniques. The cost of such investigations is usually relatively small in comparison with the cost of classical hydrological studies. The main environmental isotopes of hydrological interest are the stable isotopes deuterium (hydrogen-2), carbon-13, oxygen-18, and the radioactive isotopes tritium (hydrogen-3) and carbon-14. Isotopes of hydrogen and oxygen are ideal geochemical tracers of water because their concentrations are usually not subject to change by interaction with the aquifer material. On the other hand, carbon compounds in groundwater may interact with the aquifer material, complicating the interpretation of carbon-14 data. A few other environmental isotopes such as 32 Si and 238 U/ 234 U have been proposed recently for hydrological purposes but their use has been quite limited until now and they will not be discussed here. (author)

  13. Laser assisted aerodynamic isotope separation

    International Nuclear Information System (INIS)

    Berg, H. van den

    1985-01-01

    It is shown that the efficiency of conventional aerodynamic isotope seperation can be improved by two orders of magnitude with the aid of a relatively weak cw infrared laser which is used to induce isotopically selective condensation. Overall isotope enrichment factors in excess of 2 are obtained as compared to about 1.02 in the conventional seperation. Sulphur isotopes in SF 6 as well as Silicon isotopes in SiF 4 and Bromine isotopes in CF 3 Br are seperated on a laboratory scale. Infrared vibrational predissociation by itself and in combination with isotopically selective condensation are also shown to be effective new ways of isotope separation. (orig.) [de

  14. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    Greenland ice cores offer a unique opportunity to investigate the climate system behaviour. The objective of this PhD project is to investigate isotope modelling of present- day conditions and conduct model-data comparison using Greenland ice cores. Thus this thesis investigates how the integration...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  15. Applications of isotopes

    International Nuclear Information System (INIS)

    Kirby-Smith, J.S.

    1976-01-01

    Current and potential applications of stable isotopes as tracers in a number of biomedical and environmental areas are discussed. It is pointed out that a wide variety of problems exist in these fields whose solutions in principle are amenable to the isotopic approach. The number and diversity of these problems as well as the unique role stable isotopes can play in their solution illustrate the importance of achieving and maintaining a broad inventory of isotopic species. Experience has demonstrated unequivocally an additional overriding requirement for widespread exploration of stable isotopes by the scientific and technical community, i.e., the need for low cost availability of the materials in quantity. Some representative applications of 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, and 18 O are discussed

  16. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    the δ53Cr value of continental runoff into the ocean. The major findings were that river water is characterised by heavy δ53Cr values (+0.1‰ to +1.6‰), while soils are characterised by light δ53Cr values (-0.3‰), relative to the catchment bedrock (-0.17‰ to -0.21‰), indicating that Cr isotopes......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river water and to quantify......Chromium (Cr) stable isotopes are a useful tracer of changes in redox conditions because changes in its oxidation state are accompanied by an isotopic fractionation. For this reason the Cr isotope system is being developed as a potential tool for paleo-redox reconstruction. Dissolved Cr in seawater...

  17. Environmental isotopes (N, S, C, O, D) to determine natural attenuation processes in nitrate contaminated waters: Example of Osona (NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Vitoria, Laura [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona, Marti i Franques, s/n, 08028, Barcelona (Spain)], E-mail: lvitoria@ub.edu; Soler, Albert; Canals, Angels [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona, Marti i Franques, s/n, 08028, Barcelona (Spain); Otero, Neus [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona, Marti i Franques, s/n, 08028, Barcelona (Spain); Departament de Geologia Ambiental, Institut de Ciencies de la Terra ' Jaume Almera' , CSIC C/Lluis Sole i Sabaris s/n, Barcelona 08028 (Spain)

    2008-12-15

    Nitrate-contaminated groundwater from an aquifer in the Osona region (NE Spain) was chemically and isotopically ({delta}{sup 15}N{sub NO{sub 3}},{delta}{sup 18}O{sub NO{sub 3}},{delta}{sup 34}S{sub SO{sub 4}},{delta}{sup 18}O{sub SO{sub 4}}, {delta}D, {delta}{sup 18}O{sub H{sub 2}}{sub O} and {delta}{sup 13}C{sub DIC}) characterized. Diffuse- NO{sub 3}{sup -} contamination reached values of 366 mg/L. Nearly 75% of the 37 sampled sites had higher concentrations than the 50 mg/L in NO{sub 3}{sup -} limit for drinking water. To identify the source of pollution {delta}{sup 15}N{sub NO{sub 3}} and {delta}{sup 18}O{sub NO{sub 3}} were used with results, for most samples, in the range of pig manure NO{sub 3}{sup -}. Nitrification processes were evaluated by means of the {delta}{sup 18}O of NO{sub 3}{sup -} and water. Isotopic data suggested that natural attenuation of NO{sub 3}{sup -} was taking place. This process was confirmed using the {delta}{sup 18}O{sub NO{sub 3}} coupled with the NO{sub 3}{sup -}/Cl{sup -} ratio, avoiding the influence of continuous NO{sub 3}{sup -} inputs. A further insight on denitrification processes was obtained by analyzing the ions involved in denitrification reactions. Although the role of organic matter oxidation could neither be confirmed nor discarded, this approach showed a link between denitrification and pyrite oxidation. Therefore, in areas with no adequate infrastructure (e.g. multipiezometers), such as the one studied, this approach could be useful for implementing better water management.

  18. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  19. Isotope separation process

    International Nuclear Information System (INIS)

    1976-01-01

    The invention relates to a process for separating a given material into two or more parts, in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in the said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase UF 6 by infrared photon absorption followed by selective reaction of said excited UF 6 with atomic chlorine, bromine, or iodine to form a product which may be separated by means known in the art

  20. Radiation gradient isotope separator

    International Nuclear Information System (INIS)

    Hughes, J.L.

    1980-01-01

    A system is described for transporting, separating and storing charged particles, charged antiparticles and fully or partially ionized isotopes of any element comprising a laser beam generator, laser beam intensity profiler, a laser beam variable intensity attenuator, and means for injecting charged particles, charged antiparticles and ionized isotopes into the beam and extracting them from the system as required. The invention is particularly useful for channelling electrons and ions used for fuel pellet compression in inertial fusion systems, for separating the isotopes of elements and for the confinement of charged antiparticles and particle/antiparticle plasmas

  1. Atomic and molecular isotope separation

    International Nuclear Information System (INIS)

    Melamed, N.T.

    1979-01-01

    A method for differentially exciting a selected isotopic species in a mixture of isotopic species is described characterized in that almost the entire isotopic mixture is placed in an excited gaseous state; and a preselected isotopic species is then selectively de-excited through stimulated emission

  2. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  3. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  4. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1977-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 15 claims, 1 figure

  5. Isotope separation process

    International Nuclear Information System (INIS)

    Thomas, W.R.L.

    1979-01-01

    The instant invention relates to an improved process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same element in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than non-excited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  6. Calcium stable isotope geochemistry

    International Nuclear Information System (INIS)

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  7. Laser separation of uranium isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1981-01-01

    Method and apparatus for separating uranium isotopes are claimed. The method comprises the steps of irradiating a uranyl source material at a wavelength selective to a desired isotope and at an effective temperature for isotope spectral line splitting below about 77 deg.K., further irradiating the source material within the fluorescent lifetime of the source material to selectively photochemically reduce the excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  8. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1980-01-01

    This invention relates to the isotope separation art and, more particularly, to a selectively photon-induced energy level transition of an isotopic molecule containing the isotope to be separated and a chemical reaction with a chemically reactive agent to provide a chemical compound containing atoms of the isotope desired. In particular a description is given of a method of laser isotope separation applied to the separation of 235 UF 6 from 238 UF 6 . (U.K.)

  9. Emission spectrometric isotope analyzer

    International Nuclear Information System (INIS)

    Mauersberger, K.; Meier, G.; Nitschke, W.; Rose, W.; Schmidt, G.; Rahm, N.; Andrae, G.; Krieg, D.; Kuefner, W.; Tamme, G.; Wichlacz, D.

    1982-01-01

    An emission spectrometric isotope analyzer has been designed for determining relative abundances of stable isotopes in gaseous samples in discharge tubes, in liquid samples, and in flowing gaseous samples. It consists of a high-frequency generator, a device for defined positioning of discharge tubes, a grating monochromator with oscillating slit and signal converter, signal generator, window discriminator, AND connection, read-out display, oscillograph, gas dosing device and chemical conversion system with carrier gas source and vacuum pump

  10. Isotope toolbox turns 10

    DEFF Research Database (Denmark)

    Wenander, Fredrik; Riisager, Karsten

    2012-01-01

    REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes.......REX-ISOLDE, one of CERN’s most compact accelerators, has just celebrated its 10th anniversary. The machine’s versatility provides radioactive ion beams across the range of nuclear isotopes....

  11. Laser isotope separation

    International Nuclear Information System (INIS)

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re and Tc

  12. UWIS isotope separator

    Energy Technology Data Exchange (ETDEWEB)

    Wojtasiewicz, A. [Warsaw Univ., Inst. of Experimental Physics, Nuclear Physics Div., Warsaw (Poland)

    1997-12-31

    Since 1995 the University of Warsaw Isotope Separator group has participated in the ISOL/IGISOL project at the Heavy Ion Cyclotron. This project consists in installation of an isotope separator (on line with cyclotron heavy ion beam) with a hot plasma ion source (ISOL system) and/or with an ion guide source (IGISOL system). In the report the short description of the present status of the project is presented. 2 figs, 10 refs.

  13. Laser isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.

    1976-01-01

    The claimed invention is a method of isotope separation based on the unimolecular decomposition of vibrationally excited negative ions which are produced in the reaction of thermal electrons and molecules which have been vibrationally excited in an isotope selective manner. This method is especially applicable to molecules represented by the formula MF 6 wherein M is selected from the group consisting of U, S, W, Se, Te, Mo, Re, and Tc. 9 claims, 1 drawing figure

  14. Isotopes in environmental research

    International Nuclear Information System (INIS)

    Bowen, G.; Rozanski, K.; Vose, P.

    1990-01-01

    Radioactive and stable isotopes have long been considered a very efficient tool for studying physical and biological aspects of how the global ecosystem functions. Their applications in environmental research are numerous, embracing research at all levels. This article looks at only a few of the approaches to environmental problems that involve the use of isotopes. Special attention is given to studies of the Amazon Basin. Environmental isotopes are very efficient tools in water cycle studies. Tritium, a radioactive tracer, is especially useful in studying dynamics of water movement in different compartments of the hydrosphere, both on the local and global scales. Heavy stable isotopes of hydrogen and oxygen (deuterium and oxygen-18) provide information about steady-state characteristics of the water cycle. Isotope methods, some relatively new, have a major role in site-specific studies. Some indicative examples include: Studying turnover of organic matter. Changes in the carbon-13/carbon-12 isotopic ratio of organic matter were used to determine the respective contributions of organic carbon derived from forest and pasture. Studying biological nitrogen fixation. One of the ways nitrogen levels in soil can be maintained for productivity is by biological nitrogen fixation. Studying nitrogen availability and losses. The experimental use of nitrogen-15 is invaluable for defining losses of soil nitrogen to the atmosphere and to groundwater. Studies can similarly be done with stable and radioactive sulphur isotopes. This article indicates some potential uses of isotopes in environmental research. While the major problem of global climate change has not been specifically addressed here, the clearing of the Amazon forest, one focus of the IAEA's environmental programme, may have serious consequences for the global climate. These include substantial reduction of the amount of latent heat transported to the regions outside the tropics and acceleration of the greenhouse

  15. Isotopes in everyday life

    International Nuclear Information System (INIS)

    Seligman, H.; Gillen, V.A.

    1990-12-01

    Isotopes represent a tool which can do certain jobs better, easier, quicker, more simply and cheaper than competitive methods. Some measurements could not be done at all without the use of isotopes as there are no alternative methods available. A short review of these tools of science in their different fields is given: food and agriculture, human health applications, industry, hydrology, geology, geochemistry, geophysics and dating, environment, basic scientific research

  16. Isotope separation process

    International Nuclear Information System (INIS)

    Cabicar, J.; Stamberg, K.; Katzer, J.

    1983-01-01

    A process for separating isotopes by the method of controlled distribution is claimed. A first phase is either a solution of isotopic components and a ligand (from 10 - 6 M to a saturated solution), or a gaseous mixture of isotopic components, or a gaseous mixture of isotopic components and an inert gas. The isotopes are in the starting mixture in molar ratio from 1:10 5 to 1:10 - 5 . The second phase is a solid sorbent such as styrene-divinylbenzene ion exchangers, or bio-sorbents on the basis of mycelium of lower fungi and sorbents on the basis of cellulose, or an extraction agent such as tributyl phosphate and trioctyl amine, if need be, kept by a carrier such as teflon, silica gel and cellulose. The two-phase system exhibits non-linear equilibrium isotherm for sorption and/or desorption or for extraction and/or re-extraction. After bringing both phases into contact the rate of transport of isotopic components from one phase into another is not equal. Retardation of isotopic exchange takes place by complexation of isotopes with ligands such as cabonate, sulphate, citrate, chloride and ethylenediamine tetraacetate ions, or by using sorbents and extraction agents with chelating functional groups such as carboxyl and hyroxyl groups, groups on the basis of phosphorus, nitrogen and sulphur and/or by operating in darkness, or in the light having wave length between 2.5x10 2 and 10 9 nm. The contact time is between 10 - 2 and 10 6 s, temperature between 10 2 and 10 3 K, the number of stirrer revolutions between 10 - 2 and 10 4 revolutions per s, flow rate at column arrangement between 10 - 6 and 10 - 1 m/s and the size of particles of sorbent between 10 - 6 and 10 - 2 m

  17. Isotope separation apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.I.

    1983-01-01

    This application discloses a method for and an apparatus in which isotopes of an element in a compared are separated from each other while that compound, i.e., including a mixture of such isotopes, flows along a predetermined path. The apparatus includes a flow tube having a beginning and an end. The mixture of isotopes is introduced into the flow tube at a first introduction point between the beginning and the end thereof to flow the mixture toward the end thereof. A laser irradiates the flow tube dissociating compounds of a preselected one of said isotopes thereby converting the mixture in an isotopically selective manner. The dissociation products are removed from the tube at a first removal point between the first introduction point and the end. The dissociation product removed at the the first removal point are reconverted back into the comound thereby providing a first stage enriched compound. This first stage enriched compound is reintroduced into the flow tube at a second introduction point between the beginning thereof and the first introduction point. Further product is removed from the flow tube at a second removal point between the second introduction point and the first introduction point. The second introduction point is chosen so that the isotope composition of the first stage enriched compound is approximately the same as that of the compound in the flow tube

  18. International Isotopes Markets

    Directory of Open Access Journals (Sweden)

    Stanislaw Z. Zhiznin

    2016-01-01

    Full Text Available The paper studies world markets of stable and radioactive isotopes. Isotopes have found various applications in science, industry, agriculture and other sectors of the economy, but especially - in medicine. Nuclear medicine is developing intensively all over the world thanks to the success in the treatment of various diseases with the help of radioactive pharmaceuticals (radiopharmaceuticals. The article uses empirical data from a forecast study of the global radiopharmaceuticals market made in 2015 by a research company «Markets and Markets» for the European, North American and global markets. The paper also analyzes the statistical data on the global export and import of natural uranium, enriched and depleted uranium, plutonium, thorium and some stable isotopes of non-medical purposes, presented by a company «Trend economy» in 2014. Despite a unique industrial base for the production of isotopes created in the Soviet Union Russia occupies a modest position on the world market of nuclear medicine except for certain areas. More than 80% of isotopes, produced in USSR were consumed domestically, the export of the stable and radioactive isotopes was in equal proportions. Now the country's domestic radiopharmaceuticals market is poorly developed. To radically change the situation, it is necessary to carry out reforms that stimulate the development of nuclear medicine.

  19. Beneficial use of isotopes

    International Nuclear Information System (INIS)

    Bertel, E.; Stevens, G.H.

    1998-01-01

    The paper gives an outlook on the main isotopes currently used for beneficial applications, provides an overview on geographic distribution of isotope production capabilities and identifies the main suppliers world-wide. It analyses trends in different countries and regions, including the refurbishment and/or replacement of ageing facilities and the implementation of new capabilities. Issues related to adequate supply of isotopes and potential under or over capacity of production for some key products are discussed. The evolution of the isotope production sector is analysed. Issues such as lowering of governmental support to production facilities, emergence of international co-operation and agreements on production capabilities, and developments in non-OECD/NEA countries are addressed. The paper offers some concluding remarks on the importance of maintaining and enhancing beneficial uses of isotopes, the role of government policies, the need for co-operation between countries and between the private and public sectors. The paper addresses the role of international cooperation in making efficient use of existing isotope production capacity and investigates ways for reducing the need for investment in additional capacity. (author)

  20. Latest paleocene benthic extinction event on the southern tethyan shelf (Egypt): Foraminiferal stable isotopic (delta C-13,delta O-18) records

    OpenAIRE

    Schmitz, B; Speijer, Robert; Aubry, MP

    1996-01-01

    The dramatic global extinction of 35%-50% of benthic foraminifera species in the deep sea in the latest Paleocene and associated negative excursions in delta(13)C and delta(18)O may be related to spreading of warm, saline bottom water from subtropical Tethyan shallow regions over the sea floor worldwide, Our study of neritic sections in Egypt shows that in the southern shallow Tethys, a prominent long-term change in bottom-water chemistry, sedimentation, and benthic foraminifera fauna was ini...

  1. Transportation of medical isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, D.L.

    1997-11-19

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document.

  2. Isotope separation process

    International Nuclear Information System (INIS)

    Wexler, Sol; Young, C.E.

    1976-01-01

    Description is given of method for separating a specific isotope from a mixture of isotopes of an actinide element present as MF 6 , wherein M is the actinide element. It comprises: preparing a feed gas mixture of MF 6 in a propellant gas; passing the feed gas mixture under pressure through an expansion nozzle while heating the mixture to about 600 0 C; releasing the heated gas mixture from the nozzle into an exhaust chamber having a reduced pressure, whereby a gas jet of MF 6 molecules, MF 6 molecular clusters and propellant gas molecules is formed, the MF 6 molecules having a translational energy of about 3 eV; converting the MF 6 molecules to MF 6 ions by passing the jet through a cross jet of electron donor atoms so that an electron transfer takes place between the MF 6 - molecules and the electron donor atoms whereby the jet is now quasi-neutral, containing negative MF 6 - ions and positive donor ions; passing the quasi-neutral jet through a radiofrequency mass filter tuned to separate the MF 6 ions containing the specific isotope from the MF 6 - ions of the other isotopes and neutralizing and collecting the MF 6 molecules of the specific isotope [fr

  3. Noncovalent Hydrogen Isotope Effects

    Science.gov (United States)

    Buchachenko, A. L.; Breslavskaya, N. N.

    2018-02-01

    Zero-point energies (ZPE) and isotope effects, induced by intermolecular, noncovalent vibrations, are computed and tested by experimental data. The ZPE differences of H- and D-complexes of water with hydrogen, methane, and water molecules are about 100-300 cal/mol; they result to isotope effects IE of 1.20-1.70. Semi-ionic bonds between metal ions and water ligands in M(H2O) 6 2+ complexes are much stronger; their ZPEs are about 12-14 kcal/mol per molecule and result to IE of 1.9-2.1 at 300 K. Protonated (deuterated) water and biwater exhibit the largest ZPE differences and isotope effects; the latter are 25-28 and 12-13 for water and biwater, respectively. Noncovalent IEs contribute markedly into the experimentally measured effects and explain many anomalous and even magic properties of the effects, such as the dependence of IE on the solvents and on the presence of the third substances, enormously large isotope effects at the mild conditions, the difference between IEs measured in the reactions of individual protiated and deuterated compounds and those measured in their mixture. Noncovalent IEs are not negligible and should be taken into account to make correct and substantiated conclusions on the reaction mechanisms. The kinetic equations are derived for the total isotope effects, which include noncovalent IEs as additive factors.

  4. Transportation of medical isotopes

    International Nuclear Information System (INIS)

    Nielsen, D.L.

    1997-01-01

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document

  5. Isotope methods in hydrology

    International Nuclear Information System (INIS)

    Moser, H.; Rauert, W.

    1980-01-01

    Of the investigation methods used in hydrology, tracer methods hold a special place as they are the only ones which give direct insight into the movement and distribution processes taking place in surface and ground waters. Besides the labelling of water with salts and dyes, as in the past, in recent years the use of isotopes in hydrology, in water research and use, in ground-water protection and in hydraulic engineering has increased. This by no means replaces proven methods of hydrological investigation but tends rather to complement and expand them through inter-disciplinary cooperation. The book offers a general introduction to the application of various isotope methods to specific hydrogeological and hydrological problems. The idea is to place the hydrogeologist and the hydrologist in the position to recognize which isotope method will help him solve his particular problem or indeed, make a solution possible at all. He should also be able to recognize what the prerequisites are and what work and expenditure the use of such methods involves. May the book contribute to promoting cooperation between hydrogeologists, hydrologists, hydraulic engineers and isotope specialists, and thus supplement proven methods of investigation in hydrological research and water utilization and protection wherever the use of isotope methods proves to be of advantage. (orig./HP) [de

  6. Separation of uranium isotopes by accelerated isotope exchange reactions

    International Nuclear Information System (INIS)

    Seko, M.; Miyake, T.; Inada, K.; Ochi, K.; Sakamoto, T.

    1977-01-01

    A novel catalyst for isotope exchange reaction between uranium(IV) and uranium(VI) compounds enables acceleration of the reaction rate as much as 3000 times to make industrial separation of uranium isotopes economically possible

  7. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  8. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  9. Isotope separation system

    International Nuclear Information System (INIS)

    Lehmann, J.-C.

    1975-01-01

    A description is given of an isotope separation device comprising a system for converting into gaseous form a first and second isotope to be separated, a monochromatic excitation light source to excite the gaseous molecules of these two isotopes in a distinct manner, a first and second receiver to collect selectively the molecules of the first and second distinctly excited isotopes. The frequency FL of the excitation light is selected between a lower limit and a higher limit F2 + 1/2 LD, depending on the frequences F1 and F2 of two absorption lines near this first and second isotope. The difference DF between these two frequencies F1 and F2 is less than the Doppler width LD of each one of these lines and greater than the natural width LN of each of these two lines and also the width of line LR of the excitation light source. The probability that the molecules will be excited by this light depends on the direction of their displacement to a major and different extent for both isotopes. An ionising light source LI is set up to irradiate the seat of interaction between the excitation light and the gaseous molecules with an ionisation light able to ionise the excited molecules without ionising the molecules that are not excited. The receivers are able to collect selectively the ionised molecules. A sufficiently low gas pressure is selected for the distance between the place of interaction and the first receiver to be less than double the free mean travel of the molecules in the gas [fr

  10. Climate and isotopic tracers

    International Nuclear Information System (INIS)

    Jean-Baptiste, Ph.

    1997-01-01

    The applications of natural radioactivity and isotopic measurements in the sciences concerning Earth and its atmosphere, are numerous: carbon 14 dating with the Tandetron apparatus at the Cea, measurement of oxygen 18 in coral or sediment limestone for the determination of ocean temperature and salinity, carbon 14 dating of corals for the determination of sea level variations, deuterium content in polar ice-cap leads to temperature variations determination; isotopic measurements also enable the determination of present climate features such as global warming, oceanic general circulation

  11. Method to separate isotopes

    International Nuclear Information System (INIS)

    Coenen, H.; Neuschuetz, D.

    1980-01-01

    An extraction by means of supercritical pure gases (e.g. CD 2 ) or gas mixtures is proposed to separate isotopes, especially H/D, Li-6/Li-7, and U-235/U-238, and water or benzol is used as entrainer. The extraction shall be carried out at pressure rates of about 350 bar above the critical pressure with the temperature being by up to 100 0 C above the critical temperature. A NaCl-solution and the change of the isotopic ratio Cl-35/Cl-37 are investigated for example purpose. (UWI) [de

  12. Environmental isotope survey

    International Nuclear Information System (INIS)

    Jacovides, J.S.

    1979-03-01

    Work was initiated on the 1st of September 1971 with the objective of finding out how best to use environmental isotopes in the interpretation of the hydrology, particularly subsurface hydrology, of Cyprus through a sparse reconnaissance sampling of all the major aquifers and springs covering the whole island. The distribution of sampling was such that the survey in itself could assist in clarifying particular hydrogeologic problems, provide a better understanding of the water systems of the island, establish a general environmental isotope - framework of the hydrologic regimen of Cyprus as well as to provide the basis for specific, more detailed, studies to be undertaken subsequently

  13. Lectures in isotope geology

    International Nuclear Information System (INIS)

    Jaeger, E.; Hunziker, J.C.

    1979-01-01

    Designed for a introductory course in geochronology and the geochemistry of stable isotopes, this text has been written by recognized experts in the field. Emphasis is on the interpretation and on applications, and examples of these are offered along with each technique. Extraterrestrial applications have been avoided and the treatment of pure experimentation has been kept at a minimum. This text will be appreciated by geologists who want to learn more about methods used in isotope geology, how they can be applied, and how to gauge their usefulness. (orig.) [de

  14. High mass isotope separation arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1976-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically-identical but isotopically-different molecules by either photon-induced pure revibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically-reactive agent to form a chemical compound containing primarily the atoms of the isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically-identical but isotopically-different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope. The laser configuration used to generate the photon beam is fully described

  15. Isotope separation method and apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.L.

    1980-01-01

    A method and apparatus are specified for separating a mixture of isotopes present in a compound, preferably a gaseous compound, into two or more parts in each of which the abundances of the isotopes differ from the natural abundances of the isotopes in the compound. The invention particularly relates to carrying out a laser induced, isotopically selective conversion of gaseous molecules in such a manner as to achieve more than one stage of isotope separation along the length of the laser beam. As an example, the invention is applied to the separation of the isotopes of uranium in UF 6 , in which either the U-235 or U-238 isotope is selectively excited by means of irradiation from an infrared laser, and the selectively excited isotope converted into a product that can be recovered from UF 6 by one of a variety of methods that are described. (U.K.)

  16. Techniques for preparing isotopic targets

    International Nuclear Information System (INIS)

    Xu Guoji; Guan Shouren; Luo Xinghua; Sun Shuhua

    1987-12-01

    The techniques of making isotopic targets for nuclear physics experiments are introduced. Vacuum evaporation, electroplating, centrifugal precipitation, rolling and focused heavy-ion beam sputtering used to prepare various isotopic targets at IAE are described. Reduction-distillation with active metals and electrolytic reduction for converting isotope oxides to metals are mentioned. The stripping processes of producing self-supporting isotopic targets are summarized. The store methods of metallic targets are given

  17. Isotope separation using tunable lasers

    International Nuclear Information System (INIS)

    Snavely, B.B.

    1975-01-01

    Various processes for laser isotope separation based upon the use of the spectroscopic isotope effect in atomic and molecular vapors are discussed. Emphasis is placed upon processes which are suitable for uranium enrichment. A demonstration process for the separation of uranium isotopes using selective photoionization is described. (U.S.)

  18. Isotope effects on nuclear shielding

    International Nuclear Information System (INIS)

    Hansen, P.E.

    1983-01-01

    This review concentrates upon empirical trends and practical uses of mostly secondary isotope effects, both of the intrinsic and equilibrium types. The text and the tables are arranged in the following fashion. The most 'popular' isotope effect is treated first, deuterium isotope effects on 13 C nuclear shielding, followed by deuterium on 1 H nuclear shieldings, etc. Focus is thus on the isotopes producing the effect rather than on the nuclei suffering the effect. After a brief treatment of each type of isotope effect, general trends are dealt with. Basic trends of intrinsic isotope effects such as additivity, solvent effects, temperature effects, steric effects, substituent effects and hyperconjugation are discussed. Uses of isotope effects for assignment purposes, in stereochemical studies, in hydrogen bonding and in isotopic tracer studies are dealt with. Kinetic studies, especially of phosphates, are frequently performed by utilizing isotope effects. In addition, equilibrium isotope effects are treated in great detail as these are felt to be new and very important and may lead to new uses of isotope effects. Techniques used to obtain isotope effects are briefly surveyed at the end of the chapter. (author)

  19. Isotope shifting capacity of rock

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1980-01-01

    Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

  20. Uranium Isotopic Analysis with the FRAM Isotopic Analysis Code

    International Nuclear Information System (INIS)

    Vo, D.T.; Sampson, T.E.

    1999-01-01

    FRAM is the acronym for Fixed-Energy Response-Function Analysis with Multiple efficiency. This software was developed at Los Alamos National Laboratory originally for plutonium isotopic analysis. Later, it was adapted for uranium isotopic analysis in addition to plutonium. It is a code based on a self-calibration using several gamma-ray peaks for determining the isotopic ratios. The versatile-parameter database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration and detector type

  1. Isotopes in aquaculture research

    International Nuclear Information System (INIS)

    Ayyappan, S.; Dash, B.; Ghosh, A.S.

    1996-01-01

    The applications of isotopes in aquaculture research include areas like aquatic production process, nutrient cycles and food chain dynamics, fish nutrition, fish physiology, genetics and immunology. The radioisotopes commonly used are beta emitters. The use of different radioisotopes in aquaculture research are presented. 2 tabs

  2. Process for isotope separation

    International Nuclear Information System (INIS)

    Schuster, E.; Kersting, A.; Gebauhr, W.

    1980-01-01

    Isotope separation in UF 6 gas takes place on the principle of selective excitation by laser irradiation and separation by chemical conversion with a partner in a reaction. Atomic H, N or O or the CH 3 or CHO radicals are suitable partners in the reaction. The recombination takes place by catalytic acceleration on leaving the reaction area. (DG) [de

  3. SHELL ISOTOPE GEOCHEMISTRY

    African Journals Online (AJOL)

    ABSTRACT: The land snail Limicolaria kambeul chudeaui Germain was collected ... Key words/phrases: Ethiopia, isotope geochemistry, Lake Tilo, Limicolaria .... 1984), (c) 6'80 values of precipitation at Addis Ababa, with i 1 S.D. bars for the .... (breakfast cereal), deionised water and cuttlefish bone, the carbon and oxygen.

  4. Isotope separation process

    International Nuclear Information System (INIS)

    Cox, D.M.; Maas, E.T.

    1982-01-01

    Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO2a2)n, where a is a monovalent anion and n in an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step. The latter includes irradiating the excited molecules by a second infrared laser in order to convert the excited molecules into a separable product, or also by chemically converting the excited molecules, preferably by reaction with a gaseous reactant

  5. Isotopic effect giant resonances

    International Nuclear Information System (INIS)

    Buenerd, M.; Lebrun, D.; Martin, P.; Perrin, G.; Saintignon, P. de; Chauvin, J.; Duhamel, G.

    1981-10-01

    The systematics of the excitation energy of the giant dipole, monopole, and quadrupole resonances are shown to exhibit an isotopic effect. For a given element, the excitation energy of the transition decreases faster with the increasing neutron number than the empirical laws fitting the overall data. This effect is discussed in terms of the available models

  6. Isotopes in action

    International Nuclear Information System (INIS)

    1987-01-01

    For most people the obvious application of nuclear technology is in power generation. But there are many other uses for radioactive materials or for products made with their help. They are found in our factories, hospitals, offices and homes. ''Isotopes in Action'' looks at the many applications of radioisotopes in our society. (author)

  7. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  8. Isotopes and atomic weights

    International Nuclear Information System (INIS)

    Zhang Qinglian

    1990-01-01

    A review of the chemical and mass spectrometric methods of determining the atomic weights of elements is presented. A, special discussion is devoted to the calibration of the mass spectrometer with highly enriched isotopes. It is illustrated by the recent work on europium. How to choose the candidate element for new atomic weight determination forms the last section of the article

  9. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    Koenig, Z.M.; Ruhter, W.D.; Gunnink, R.

    1990-01-01

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  10. Application of the isotopic index in isotope geochemical investigation

    International Nuclear Information System (INIS)

    Schuetze, H.

    1982-06-01

    A method is described which allows to calculate approximately isotope exchange equilibria between different crystalline silicates. The algorithm uses a newly introduced isotopic index. It is defined using isotopic increments of the variant types of silicatic bonds. This isotopic index gives a quantitative measure of the ability to enrich 18 O or 30 Si, respectively. The dependence of isotopic fractionations on temperature can be calculated approximately by means of the isotopic index, too. On this theoretical base some problems of magmatism and two varieties of an isotope geochemical model of the evolution of the Earth's crust are treated. Finally, the possibility is demonstrated to give prognostic statements about the likelihood of ore bearing of different granites. (author)

  11. Isotopic separation by ion chromatography

    International Nuclear Information System (INIS)

    Albert, M.G.; Barre, Y.; Neige, R.

    1994-01-01

    The isotopic exchange reaction and the isotopic separation factor are first recalled; the principles of ion chromatography applied to lithium isotope separation are then reviewed (displacement chromatography) and the process is modelled in the view of dimensioning and optimizing the industrial process; the various dimensioning parameters are the isotopic separation factor, the isotopic exchange kinetics and the material flow rate. Effects of the resin type and structure are presented. Dimensioning is also affected by physico-chemical and hydraulic parameters. Industrial implementation features are also discussed. 1 fig., 1 tab., 5 refs

  12. Physics with isotopically controlled semiconductors

    International Nuclear Information System (INIS)

    Haller, E.E.

    1994-08-01

    Control of the isotopic composition of semiconductors offers a wide range of new scientific opportunities. In this paper a number of recent results obtained with isotopically pure as well as deliberately mixed diamond and Ge bulk single crystals and Ge isotope superlattices will be reviewed. Isotopic composition affects several properties such as phonon energies, bandstructure and lattice constant in subtle but theoretically well understood ways. Large effects are observed for thermal conductivity, local vibrational modes of impurities and after neutron transmutation doping (NTD). Several experiments which could profit greatly from isotope control are proposed

  13. Isotope separation process

    International Nuclear Information System (INIS)

    Kaldor, A.; Rabinowitz, P.

    1979-01-01

    A method of separating the isotopes of an element is described, which comprises the steps of (i) subjecting molecules of a gaseous compound of the element simultaneously to two infrared radiations of different wavelengths, the first radiation having a wavelength which corresponds to an absorption band of the compound, which in turn corresponds to a mode of molecular motion in which there is participation by atoms of the element, and the second radiation having a power density greater than 10 6 watts per cm 2 , thereby exciting molecules of the compound in an isotopically selective manner, this step being conducted in such manner that the excited molecules either receive a level of energy sufficient to cause them to undergo conversion by unimolecular decomposition or receive a level of energy sufficient to cause them to undergo conversion by reaction with molecules of another gas present for that purpose; and (ii) separating and recovering converted molecules from unconverted molecules. (author)

  14. Decontamination of radioactive isotopes

    International Nuclear Information System (INIS)

    Despotovic, R.; Music, S.; Subotic, B.; Wolf, R.H.H.

    1979-01-01

    Removal of radioactive isotopes under controlled conditions is determined by a number of physical and chemical properties considered radiocontaminating and by the characteristics of the contaminated object. Determination of quantitative and qualitative factors for equilibrium in a contamination-decontamination system provides the basis for rational and successful decontamination. The decontamination of various ''solid/liquid'' systems is interesting from the scientific and technological point of view. These systems are of great importance in radiation protection (decontamination of various surfaces, liquids, drinking water, fixation or collection of radiocontaminants). Different types of decontamination systems are discussed. The dependence of rate and efficiency of the preparation conditions and on the ageing of the scavenger is described. The influence of coagulating electrolyte on radioactive isotope fixation efficiency was also determined. The fixation of fission radionuclide on oxide scavengers has been studied. The connection between fundamental investigations and practical decontamination of the ''solid/liquid'' systems is discussed. (author)

  15. Cyclotrons for isotope production

    International Nuclear Information System (INIS)

    Milton, B.F.; Stevenson, N.R.

    1995-06-01

    Cyclotrons continue to be efficient accelerators for radioisotope production. In recent years, developments in the accelerator technology have greatly increased the practical beam current in these machines while also improving the overall system reliability. These developments combined with the development of new isotopes for medicine and industry, and a retiring of older machines indicates a strong future for commercial cyclotrons. In this paper we will survey recent developments in the areas of cyclotron technology, and isotope production, as they relate to the new generation of commercial cyclotrons. We will also discuss the possibility of systems capable of extracted energies up to 100 MeV and extracted beam currents of up to 2.0 mA. (author). 6 refs., 2 tabs., 3 figs

  16. Rechargeable radioactive isotope generator

    International Nuclear Information System (INIS)

    Thornton, A.K.; Cerone, F.E.

    1978-01-01

    The description is given of a rechargeable radioactive isotope generator having the following features: a box containing a transport shield, a shielded generator including elements for the absorption and holding of the parent isotope, an eluant tank, a first pipe causing this tank to communicate with the transport shield, a second pipe causing this transport shield to communicate with the shielded generator and a third pipe placing the shielded generator in communication with the outside of the unit. It also includes a shelf across the external front part of the unit a part of which is shielded by external components, a shielded elution flask in which the eluate is poured and a filter set at a point between the flask and the third pipe [fr

  17. Equipment for isotope diagnostics

    International Nuclear Information System (INIS)

    Platz, W.

    1976-01-01

    The invention concerns an improvement of equipment for isotope diagnostics allowing to mark special intensity ranges of the recorded measurements by means of different colors. For undisturbed operation it is of advantage to avoid electric circuits between movable and unmovable parts of the color recorder. According to the invention, long gear wheels of glass fiber-reinforced polyamide are used for these connections. (ORU) [de

  18. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  19. Stable-isotope studies

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Structures of bacteriochlorophyll b and the Krasnovskii photoreduction products of chlorophyll a are given. All 55 13 C and 4 15 N NMR transitions in chlorophyl a and its magnesium-free derivative pheophytin a were assigned. ESR of triplet states of chlorophylls a, b, c/sub z/, and c 2 and bacteriochlorophyll a are reported. Experiments in the cultivation of 13 C-enriched morning glory plants indicated that the isotope enrichment can produce observable morphological changes. (U.S.)

  20. Protected isotope heat source

    International Nuclear Information System (INIS)

    Burns, R.K.; Shure, L.I.; Katzen, E.D.

    1975-01-01

    A radioactive isotope capsule is disposed in a container (heat shield) which will have a single stable trim attitude when reentering the earth's atmosphere and while falling to earth. The center of gravity of the heat source is located forward of the midpoint between the front face and the rear face of the container. The capsule is insulated from the front face of the container but not from the rear surface of the container. (auth)

  1. Isotopes and agriculture

    International Nuclear Information System (INIS)

    Malavolta, E.

    1988-01-01

    The agriculture is defined as the art of desturbing the ecosystems in economical terms with the minimum of irreversible damage. Man survival in the biosphere will depend on its ability of using four technologies - mechanization, fertilizers, irrigation and pest disease control. The isotopes are usefull to establish means of producing more food and to preserve it; and clains of unbearable damages to the ecosystems caused by fertilizers and pesticides are not true, are presented. (author) [pt

  2. The isotope correlation experiment

    International Nuclear Information System (INIS)

    Koch, L.; Schoof, S.

    1983-01-01

    The ESARDA working group on Isotopic Correlation Techniques, ICT and Reprocessing Input Analysis performed an Isotope Correlation Experiment, ICE with the aim to check the feasibility of the new technique. Ten input batches of the reprocessing of the KWO fuel at the WAK plant were analysed by 4 laboratories. All information to compare ICT with the gravimetric and volumetric methods was available. ICT combined with simplified reactor physics calculation was included. The main objectives of the statistical data evaluation were detection of outliers, the estimation of random errors and of systematic errors of the measurements performed by the 4 laboratories. Different methods for outlier detection, analysis of variances, Grubbs' analysis for the constant-bias model and Jaech's non-constant-bias model were applied. Some of the results of the statistical analysis may seem inconsistent which is due to the following reasons. For the statistical evaluations isotope abundance data (weight percent) as well as nuclear concentration data (atoms/initial metal atoms) were subjected to different outlier criteria before being used for further statistical evaluations. None of the four data evaluation groups performed a complete statistical data analysis which would render possible a comparison of the different methods applied since no commonly agreed statistical evaluation procedure existed. The results prove that ICT is as accurate as conventional techniques which have to rely on costly mass spectrometric isotope dilution analysis. The potential of outlier detection by ICT on the basis of the results from a single laboratory is as good as outlier detection by costly interlaboratory comparison. The application of fission product or Cm-244 correlations would be more timely than remeasurements at safeguards laboratories

  3. Isotopic safeguards statistics

    International Nuclear Information System (INIS)

    Timmerman, C.L.; Stewart, K.B.

    1978-06-01

    The methods and results of our statistical analysis of isotopic data using isotopic safeguards techniques are illustrated using example data from the Yankee Rowe reactor. The statistical methods used in this analysis are the paired comparison and the regression analyses. A paired comparison results when a sample from a batch is analyzed by two different laboratories. Paired comparison techniques can be used with regression analysis to detect and identify outlier batches. The second analysis tool, linear regression, involves comparing various regression approaches. These approaches use two basic types of models: the intercept model (y = α + βx) and the initial point model [y - y 0 = β(x - x 0 )]. The intercept model fits strictly the exposure or burnup values of isotopic functions, while the initial point model utilizes the exposure values plus the initial or fabricator's data values in the regression analysis. Two fitting methods are applied to each of these models. These methods are: (1) the usual least squares fitting approach where x is measured without error, and (2) Deming's approach which uses the variance estimates obtained from the paired comparison results and considers x and y are both measured with error. The Yankee Rowe data were first measured by Nuclear Fuel Services (NFS) and remeasured by Nuclear Audit and Testing Company (NATCO). The ratio of Pu/U versus 235 D (in which 235 D is the amount of depleted 235 U expressed in weight percent) using actual numbers is the isotopic function illustrated. Statistical results using the Yankee Rowe data indicates the attractiveness of Deming's regression model over the usual approach by simple comparison of the given regression variances with the random variance from the paired comparison results

  4. Dual isotope assays

    International Nuclear Information System (INIS)

    Smith, G.F.W.; Stevens, R.A.J.; Jacoby, B.

    1980-01-01

    Dual isotope assays for thyroid function are performed by carrying out a radio-immunoassay for two of thyroxine (T4), tri-iodothyronine (T3), thyroid stimulating hormone (TSH), and thyroxine binding globulin (TBG), by a method wherein a version of one of the thyroid components, preferably T4 or T3 is labelled with Selenium-75 and the version of the other thyroid component is labelled with a different radionuclide, preferably Iodine-125. (author)

  5. Electrochemically controlled iron isotope fractionation

    Science.gov (United States)

    Black, Jay R.; Young, Edward D.; Kavner, Abby

    2010-02-01

    Variations in the stable isotope abundances of transition metals have been observed in the geologic record and trying to understand and reconstruct the physical/environmental conditions that produced these signatures is an area of active research. It is clear that changes in oxidation state lead to large fractionations of the stable isotopes of many transition metals such as iron, suggesting that transition metal stable isotope signatures could be used as a paleo-redox proxy. However, the factors contributing to these observed stable isotope variations are poorly understood. Here we investigate how the kinetics of iron redox electrochemistry generates isotope fractionation. Through a combination of electrodeposition experiments and modeling of electrochemical processes including mass-transport, we show that electron transfer reactions are the cause of a large isotope separation, while mass transport-limited supply of reactant to the electrode attenuates the observed isotopic fractionation. Furthermore, the stable isotope composition of electroplated transition metals can be tuned in the laboratory by controlling parameters such as solution chemistry, reaction overpotential, and solution convection. These methods are potentially useful for generating isotopically-marked metal surfaces for tracking and forensic purposes. In addition, our studies will help interpret stable isotope data in terms of identifying underlying electron transfer processes in laboratory and natural samples.

  6. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  7. Isotope effects on chemical equilibria

    International Nuclear Information System (INIS)

    Golding, P.D.

    1974-01-01

    The thermodynamic equilibrium constants of three deuterated substituted acetic acids are reported. The calculation of secondary isotope effects of the second kind for the three isotopic acid pairs has been accomplished by the appropriate comparison of thermodynamic equilibrium constants, and by the comparison of isotopic slopes. The effect of substituent variation on the isotope effects reported here disqualifies the simple inductive model as a legitimate description of secondary isotope effects of the second kind. The correlation of diminishing isotope effect per deuterium atom with increasing acidity is also invalidated by the present results. The syntheses of 9-thia-9,10-dihydrophenanthrene-9-oxide and thioxanthene-10-oxide are described. These compounds have been partially deuterated at their respective methylene positions. Spectral evidence indicates stereoselectivity of the methylene protons in the exchange reactions of both compounds. (author)

  8. Therapeutic use of radioactive isotopes

    CERN Document Server

    Caroline Duc

    2013-01-01

    In December, researchers from ISOLDE-CERN, the Paul Scherrer Institute (PSI) and the Institut Laue-Langevin (ILL) published the results of an in vivo study which successfully proved the effectiveness of four terbium isotopes for diagnosing and treating cancerous tumours.   Four terbium isotopes suitable for clinical purposes. “ISOLDE is the only installation capable of supplying terbium isotopes of such purity and intensity in the case of three out of the four types used in this study,” explains Karl Johnson, a physicist at ISOLDE.  “Producing over a thousand different isotopes, our equipment offers the widest choice of isotopes in the world!” Initially intended for fundamental physics research, ISOLDE has diversified its activities over time to invest in various projects in the materials science, biochemistry and nuclear medicine fields. The proof-of-concept study has confirmed that the four terbium isotopes 149Tb, 152Tb, 155Tb produ...

  9. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  10. French days on stable isotopes

    International Nuclear Information System (INIS)

    2000-01-01

    These first French days on stable isotopes took place in parallel with the 1. French days of environmental chemistry. Both conferences had common plenary sessions. The conference covers all aspects of the use of stable isotopes in the following domains: medicine, biology, environment, tracer techniques, agronomy, food industry, geology, petroleum geochemistry, cosmo-geochemistry, archaeology, bio-geochemistry, hydrology, climatology, nuclear and particle physics, astrophysics, isotope separations etc.. Abstracts available on CD-Rom only. (J.S.)

  11. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1982-01-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for nondestructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Material Research Collection and does not designate whether a sample is out on loan or in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  12. Oxygen and hydrogen isotope geochemistry of Cretaceous bentonites and shales from the Disturbed Belt, Montana

    International Nuclear Information System (INIS)

    Eslinger, E.V.; Yeh Hsuehwen

    1986-01-01

    The mineralogy, deltaO 18 , and deltaD of the 18 of the 18 of 18 , data for the 18 of bulk bentonite is 1 to 3 per mille more negative than the deltaO 18 of the 18 of several size fractions of clay-sized quartz separated from the bentonite varies from +11 per mille to +24 per mille. Results are presented and discussed. (author)

  13. Chemical separation of boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF/sub 3/ gas and the liquid molecular addition compounds of BF/sub 3/. Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF/sub 3/ solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references.

  14. Melatonin labeled with hydrogen isotopes

    International Nuclear Information System (INIS)

    Dmitrevskaya, L.I.; Smushkevich, Yu.I.; Kurkovskaya, L.N.; Ponomarenko, N.K.; Suvorov, N.N.

    1989-01-01

    A study has been made of isotope exchange between melatonin and deuterium (D 2 O) or tritium (HTO) oxide under different conditions. The ease of isotope exchange for the indole ring hydrogens of melatonin in an acidic medium decreases over the series H 4 > H 2 H 6 >> H 7 , enabling the authors to process a route for production of melatonin labeled with hydrogen isotopes at positions 4,6, and 2 of the indole ring. A method has been suggested for producing melatonin labeled with hydrogen isotopes at position 2 by desulfurization of 2-(2,4-dinitro-phenylsulfenyl)melatonin at Ni(Re) (D)

  15. Melatonin labelled by hydrogen isotopes

    International Nuclear Information System (INIS)

    Dmitrevskaya, L.I.; Smushkevich, Yu.I.; Kurkovskaya, L.N.; Ponomarenko, N.K.; Suvorov, N.N.

    1988-01-01

    Isotope exchange of melatonin with deuterium (D 2 O) and tritium (HTO) oxides under different conditions is studied. Simplicity of isotope exchange of hydrogens of the indole ring of melatonin in the acidic medium decreases in series H 4 >H 2 >H 6 >>H 7 , that permits to suggest the way of melatonin preparation labelled by hydrogen isotopes in positions 4,6 and 2 of the indole ring. The way of melatonin preparation labelled by hydrogen isotopes in position 2 according to the reaction of desulfation 2-(2,4-dinitrophenylsulphenyl) melatonin at catalyst Ni(Re)(D) is suggested

  16. Development of Stable Isotope Technology

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Han, Jae Min

    2009-03-01

    KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

  17. Isotope separation by ion waves

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1978-01-01

    One of the isotopes of an element having several isotopes can be separated from the others in a dense, neutral plasma. Thus initially a neutral plasma is prepared including the element in question. This may consist of positive ions and negative electrons or alternatively of positive and negative ions, or else of a mixture of positive ions, negative ions and electrons. The plasma may then be injected into a magnetic field or may be generated in the field where more energy is imparted to a selected isotope than to the others. Finally, the isotopes are separated from each other on the basis of their differential energies. For example, the selected isotope may be given more energy than the others by stimulating it within the plasma at its resonant frequency which may be close to the cyclotron frequency, either by an electric field or by a magnetic field. In order to excite the other isotope, a different resonant frequency is required which depends on the plasma density, the relative concentration of electrons if the plasma contains electrons, the strength of the magnetic field, the ratio of charge to mass of the isotope, and possibly on the physical parameters of the plasma apparatus itself, such as the ratio of the length of the plasma column to its radius. The more energetic isotope may be separated by energy dependent chemical reactions, it may be collected by a positively biased probe or else the isotopes may be separated from each other by magnetic fields or in various other ways

  18. Chemical separation of boron isotopes

    International Nuclear Information System (INIS)

    Palko, A.A.

    1978-06-01

    This is the final report of the research performed at ORNL on the chemical fractionation of boron isotopes between BF 3 gas and the liquid molecular addition compounds of BF 3 . Thirty compounds were studied, ten of them in detail. Graphs and equations are given for variation of isotopic equilibrium constant, vapor pressure, and BF 3 solubility as a function of temperature. Rate of isotopic exchange and melting points were determined. Several of the compounds are likely candidates for use in a gas-liquid countercurrent exchange system for large-scale separation of boron isotopes. 23 figs, 53 tables, 39 references

  19. Isotope separation by magnetic fields

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1978-01-01

    One of the isotopes of an element having several isotopes can be separated from the others in a dense, neutral plasma. Thus initially a neutral plasma is prepared including the element in question. This may consist of positive ions and negative electrons or alternatively of positive and negative ions, or else of a mixture of positive ions, negative ions and electrons. The plasma may then be injected into a magnetic field or may be generated in the field where more energy is imparted to a selected isotope than to the others. Finally, the isotopes are separated from each other on the basis of their differential energies. For example, the selected isotope may be given more energy than the others by stimulating it within the plasma at its resonant frequency which may be close to the cyclotron frequency, either by an electric field or by a magnetic field. In order to excite the other isotope, a different resonant frequency is required which depends on the plasma density, the relative concentration of electrons if the plasma contains electrons, the strength of the magnetic field, the ratio of charge to mass of the isotope, and possibly on the physical parameters of the plasma apparatus itself, such as the ratio of the length of the plasma column to its radius. The more energetic isotope may be separated by energy dependent chemical reactions, it may be collected by a positively biased probe or else the isotopes may be separated from each other by magnetic fields or in various other ways

  20. Advanced isotope separation

    International Nuclear Information System (INIS)

    1982-01-01

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  1. Isotope effect and isotope separation. A chemist's view

    International Nuclear Information System (INIS)

    Ishida, Takanobu

    2002-01-01

    What causes the isotope effects (IE)? This presentation will be centered around the equilibrium isotope effects due to the differences in the nuclear masses. The occurrence of the equilibrium constant, K, of isotope exchange reactions which differ from the values predicted by the classical theory of statistical mechanics, K cl , is explored. The non-classical K corresponds to the unit-stage separation factor, α, that is different from unity and forms a basis of an isotope separation process involving the chemical exchange reaction. Here, the word 'chemical exchange' includes not only the isotope exchange chemical reactions between two or more chemical species but also the isotope exchanges involving the equilibria between liquid and vapor phases and liquid-gas, liquid solution-gas, liquid-liquid, and solid-liquid phases. In Section I, origins of the isotope effect phenomena will be explored and, in the process, various quantities used in discussions of isotope effect that have often caused confusions will be unambiguously defined. This Section will also correlate equilibrium constant with separation factor. In Section II, various forms of temperature-dependence of IE and separation factor will be discussed. (author)

  2. Container for hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-12

    A container is described for storage, shipping and and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same. The container is compact, safe against fracture or accident, and is reusable. It consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and is retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates.

  3. Cold regions isotope applications

    International Nuclear Information System (INIS)

    Perrigo, L.D.; Divine, T.E.

    1976-04-01

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids

  4. Applied isotope hydrogeology

    International Nuclear Information System (INIS)

    Pearson, F.J. jr; Balderer, W.; Gautschi, A.

    1991-01-01

    This volume is a report on the isotopic investigations of ground-water in northern Switzerland and adjacent regions carried out since 1981 by Nagra, the Swiss National Cooperation for the Storage of Radio-active Waste. This study was undertaken to support a programme assessing potential sites for nuclear waste repositories. It includes measurements on a large number of stable- and radioisotopes and noble gases, supported by complete water chemical analyses and many rock and mineral analyses. A synthesis and interpretation of the data, along with the data themselves, are given here. (author). refs.; figs.; tabs

  5. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1983-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure, particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation column. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale multi-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  6. Chromatographic hydrogen isotope separation

    International Nuclear Information System (INIS)

    Aldridge, F.T.

    1981-01-01

    Intermetallic compounds with the CaCu5 type of crystal structure , particularly LaNiCo and CaNi5, exhibit high separation factors and fast equilibrium times and therefore are useful for packing a chromatographic hydrogen isotope separation colum. The addition of an inert metal to dilute the hydride improves performance of the column. A large scale mutli-stage chromatographic separation process run as a secondary process off a hydrogen feedstream from an industrial plant which uses large volumes of hydrogen can produce large quantities of heavy water at an effective cost for use in heavy water reactors

  7. Isotope diagnostics apparatus

    International Nuclear Information System (INIS)

    Herrschaft, H.

    1976-01-01

    The invention relates to a measuring probe for an isotope diagnostics apparatus to determine the distribution of radioactive substances in a body by measuring the radiation emanating from this body by means of a multiplicity of measuring probes directed simultaneously towards areas of measuring surfae and carried in guidances of a holding block. The measuring results of the individual probes are recorded separately, thus allowing the possibility of being evaluated separately, too. Measuring probes of this kind are used in multi-channel measuring objects and are useful particularly for determining the regional cerebral blood flow. (orig./ORU) [de

  8. Container for hydrogen isotopes

    International Nuclear Information System (INIS)

    1976-01-01

    A container is described for storage, shipping and and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same. The container is compact, safe against fracture or accident, and is reusable. It consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and is retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates

  9. Isotopic Thermionic Generator

    International Nuclear Information System (INIS)

    Clemot, M.; Devin, B.; Durand, J.P.

    1967-01-01

    This report describes the general design of a thermionic direct conversion space generator. The power source used is a radioisotope. Two radioisotopes are considered: Pu 238 and Cm 244. The system is made up of a heat pipe concentrating the thermal flux from the isotope to the emitter, and of a second heat pipe evacuating the waste heat from the collector to the outer wall used as radiating panel. Calculations are given in the particular case of a 100 electrical watts output power. (authors) [fr

  10. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, A.

    1977-01-01

    In a method for the separation of isotopes of uranium in UF 6 , the UF 6 is subjected to ir radiation at a predetermined wavelength or set of wavelengths for less than 10 -3 sec in such a manner that at least 0.1% of the 235 UF 6 molecules absorb an energy of more than 2000 cm -1 . The excited UF 6 is then reacted with a gaseous reagent, F 2 , Cl 2 , or Br 2 , to produce a product which is then recovered by means known in the art

  11. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  12. Isotope anomalies in oxygen isotope exchange equilibrium systems

    International Nuclear Information System (INIS)

    Kotaka, M.

    1997-01-01

    The purpose of the present work is to elucidate the isotope anomalies in oxygen isotope exchange equilibrium systems, according to the calculations of the equilibrium constants for oxygen isotopic exchange reactions, and the calculations of the oxygen isotope separation factors between two phases. The equilibrium constants (K65, K67, K68 and K69) of 16 O- 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O exchange reactions between diatomic oxides were calculated in a wide temperature range on the basis of quantum statistical mechanics. Many equilibrium constants showed the anomalous mass effects, and then had the crossover temperatures and the mass independent fractionation (MIF) temperatures which held K67 = K65, K67 = K68, or K67 = K69, etc. For example, the equilibrium constants for the reactions between OH and the other diatomic oxides (MO) showed the anomalous mass effects, when M was Li, Na, Mg, K, Fe, Al, Ge, Zr, Pt, etc. The 16 O 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O oxygen isotope separation factors (S65, S67, S68 and S69) between two phases were calculated, when OH and CO were in the first phase, and SiO was in the second phase. Although the oxygen isotopic exchange equilibria in the two phases had no MIF and crossover temperatures, the separation factors showed the anomalous mass effects and had the temperatures. According to what is called the normal mass effects for the equilibrium constant of isotopic exchange reaction, the value of InK68/InK67 is 1.885. Therefore, the value of InS68/InS67 should be 1.885 too. The value calculated, however, widely changed. It can be concluded from the results obtained in the present work that some oxygen isotopic exchange equilibria cause the anomalous mass effects, the anomalous oxygen isotope separation factors, and then isotope anomalies

  13. Zirconium isotope separation process

    International Nuclear Information System (INIS)

    Peterson, S.H.; Lahoda, E.J.

    1988-01-01

    A process is described for reducing the amount of zirconium 91 isotope in zirconium comprising: forming a first solution of (a) a first solvent, (b) a scavenger, and (c) a zirconium compound which is soluble in the first solvent and reacts with the scavenger when exposed to light of a wavelength of 220 to 600 nm; irradiating the first solution with light at the wavelength for a time sufficient to photoreact a disproportionate amount of the zirconium compound containing the zirconium 91 isotope with the scavenger to form a reaction product in the first solution; contacting the first solution, while effecting the irradiation, with a second solvent which is immiscible with the first solvent, which the second solvent is a preferential solvent for the reaction product relative to the first solvent, such that at least a portion of the reaction product is transferred to the second solvent to form a second solution; and separating the second solution from the first solution after the contacting

  14. Isotope techniques for hydrology

    International Nuclear Information System (INIS)

    1964-01-01

    In the body of the Panel's report specific conclusions and recommendations are presented in the context of each subject. The general consensus of the Panel is as follows: by the study of this report, the 1961 Panel report, the Proceedings of the March 1963 Tokyo Symposium and other reports of research and technological advances, isotope-technique applications to hydrologic problems have provided some useful avenues for understanding the nature of the hydrologic cycle and in the solution of specific engineering problems. Some techniques are developed thoroughly enough for fairly routine application as tools for use in the solution of practical problems, but further research and development is needed on other concepts to determined whether or not they can be beneficially applied to either research or engineering problems. A concerted effort is required on the part of both hydrologists and isotope specialists working as teams to assure that proper synthesis of scientific advances in the respective fields and translation of these advances into practical technology is achieved

  15. Isotopes in agriculture

    International Nuclear Information System (INIS)

    1983-01-01

    Part 1: The stable isotope of nitrogen 15N has become widely used as tracer in agriculture, medicine and biology research. The film gives an overview of the sample preparation and analytical procedures followed in the analysis of the nitrogen isotopic composition (14N/15N ratio) by optical emission spectrometry at the Seibersdorf Laboratory. The subsampling of plant material and the several steps of chemical pretreatment such as Kjeldahl digestion, distillation, titration and adjustment of the proper N concentration in the extract are demonstrated. The preparation of the discharge tubes is shown in detail. Final measurement of the 14N/15N ratio is carried out with the NOI-5 and JASCO emission spectrometers. Part 2: This training film deals with the use of 32P-labelled materials in field and greenhouse experimentation in soil-plant relationships studies. All technical aspects, including safe handling and radiation protection procedures to be considered in the layout and harvesting of field experiments are documented in detail. Procedures followed up in the evaluation of P fertilizers such as rock phosphates under greenhouse conditions are described. Several soil injection techniques available for determination of the root activity pattern of trees are shown

  16. Isotope techniques for hydrology

    Energy Technology Data Exchange (ETDEWEB)

    1964-01-01

    In the body of the Panel's report specific conclusions and recommendations are presented in the context of each subject. The general consensus of the Panel is as follows: by the study of this report, the 1961 Panel report, the Proceedings of the March 1963 Tokyo Symposium and other reports of research and technological advances, isotope-technique applications to hydrologic problems have provided some useful avenues for understanding the nature of the hydrologic cycle and in the solution of specific engineering problems. Some techniques are developed thoroughly enough for fairly routine application as tools for use in the solution of practical problems, but further research and development is needed on other concepts to determined whether or not they can be beneficially applied to either research or engineering problems. A concerted effort is required on the part of both hydrologists and isotope specialists working as teams to assure that proper synthesis of scientific advances in the respective fields and translation of these advances into practical technology is achieved.

  17. Method of isotope separation

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, R K

    1975-05-22

    Isotopes of a gaseous compound can be separated by multi-infrared photoabsorption which follows a selective dissociation of the excited molecules by single photon absorption of photons of visible or UV radiation. The process involves three steps. Firstly, the molecules to be separated are irradiated with a high-energy IR laser, whereby the molecules of the compound containing the lighter isotopes are preferably excited. They are then irradiated by a second laser with UV or visible light whose frequency of radiation brings the excited molecules into a form in which they can be separated from the non-excited molecules. The third step is the reformation of the substances according to known methods. A power density of at least 10/sup 4/ watt/cm/sup 2/ per torr gas pressure with an irradiation time of 10/sup -10/ to 5 x 10/sup -5/ seconds in the presence of a second gas with at least 5 times higher partial pressure is necessary for the IR radiation. The method may be used for UF/sub 6/ for which an example is given here.

  18. Isotopic geochemistry at Wairakei

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1985-12-01

    Deuterium measurements on geothermal water at Wairakei are consistent with the water being derived from rainfall which has percolated down from the surface. The oxygen-18 content, however, is enriched compared to average rainfall. This 18 O shift is due to isotopic exchange between water and rock at greater-than-explored depths. The magnitude of the shift implied that the mass ration (W/R) of water that has passed through the system (W) to the rock it has exchanged with (R) is about 1 assuming open (i.e. single-pass) conditions. (The ratio is about 2 if it has been a closed system, but this is thought to be less likely). The residence time of water underground cannot be determined from tritium and carbon-14 measurements at present, but arguments based on the argon isotope and deuterium contents suggest mean residence times of a few tens of thousand years. The water-rock ratio and large natural outflow of thermal water prior to exploitation are consistent with this. The 18 O content of the water has changed only slightly, and the D content not at all, during exploitation at Wairakei (measurements from 1963, 1974 and 1981). An initial tendency for the 18 O to increase because of steam loss (also shown more clearly by chloride), has been followed by decrease of 18 O (and chloride) because of dilution with infiltrating near-surface water in parts of the field

  19. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    McConnell, D.B.

    1975-01-01

    Gaseous isotopes are separated from a mixture in a vertically elongated chamber by subjecting the mixture to a nonuniform transverse electric field. Dielectrophoretic separation of the isotopes is effected, producing a transverse temperature gradient in the chamber, thereby enhancing the separation by convective countercurrent flow. In the example given, the process and apparatus are applied to the production of heavy water from steam

  20. Boron isotopes in geothermal systems

    International Nuclear Information System (INIS)

    Aggarwal, J.

    1997-01-01

    Boron is a highly mobile element and during water-rock reactions, boron is leached out of rocks with no apparent fractionation. In geothermal systems where the water recharging the systems are meteoric in origin, the B isotope ratio of the geothermal fluid reflects the B isotope ratio of the rocks. Seawater has a distinctive B isotope ratio and where seawater recharges the geothermal system, the B isotope ratio of the geothermal system reflects the mixing of rock derived B and seawater derived B. Any deviations of the actual B isotope ratio of a mixture reflects subtle differences in the water-rock ratios in the cold downwelling limb of the hydrothermal system. This paper will present data from a variety of different geothermal systems, including New Zealand; Iceland; Yellowston, USA; Ibusuki, Japan to show the range in B isotope ratios in active geothermal systems. Some of these systems show well defined mixing trends between seawater and the host rocks, whilst others show the boron isotope ratios of the host rock only. In geothermal systems containing high amounts of CO 2 boron isotope ratios from a volatile B source can also be inferred. (auth)

  1. Basic methods of isotope analysis

    International Nuclear Information System (INIS)

    Ochkin, A.V.; Rozenkevich, M.B.

    2000-01-01

    The bases of the most applied methods of the isotope analysis are briefly presented. The possibilities and analytical characteristics of the mass-spectrometric, spectral, radiochemical and special methods of the isotope analysis, including application of the magnetic resonance, chromatography and refractometry, are considered [ru

  2. Lead isotope in mineral exploration

    International Nuclear Information System (INIS)

    Gulson, B.L.

    1986-01-01

    This book provides an up-to-date state-of-the-art review of lead isotopes in mineral exploration. Beginning with an historical review on suggested uses of lead isotopes in mineral exploration, the author then outlines the theoretical aspects of lead isotopes and illustrates that the method is based on well-known principles of radioactive decay, from which isotopic signatures for different styles of mineralization are derived. The varying isotopic signatures are then introduced. The major part of the book details over 40 case histories for base and precious metals, uranium and tin using sampling media such as sulfides, gossans, soils, weathered bedrock, vegetation and groundwaters. Advantages and disadvantages of each are discussed. Examples are given of the use of lead isotopes in testing conceptual models for exploration. The success rate and cost-effectiveness of the method are illustrated by actual exploration examples. Analytical advances which should lower the cost of the method and future uses are outlined. Many of the case histories use recently published or unpublished data, 27 tables of which are given in an appendix. Details of sampling, the methods for obtaining the isotope ratios, and a commercially-available integrated lead isotope service are also provided. (Auth.)

  3. Method for separating krypton isotopes

    International Nuclear Information System (INIS)

    Porter, J.T.

    1980-01-01

    Methods and apparatus for separating krypton isotopes utilizing low temperature selective infrared excitation of 85krypton difluoride in an isotopic compound mixture. Multiphoton ir excitation and uv excitation techniques are used, as well as cryogenic matrix isolation and inert buffer gas isolation techniques

  4. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1980-12-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for non-destructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Materials Research Collection and does not designate whether a sample is out on loan or in reprocessing

  5. Calcium isotopes in wine

    Science.gov (United States)

    Holmden, C. E.

    2011-12-01

    The δ 44/40Ca values of bottled wine vary between -0.76% to -1.55% on the seawater scale and correlate weakly with inverse Ca concentration and Mg/Ca ratio, such that the lowest δ 44/40Ca values have the highest Ca concentrations and lowest Mg/Ca ratios. The correlation is notable in the sense that the measured wines include both whites and reds sampled from different wine growing regions of the world, and cover a wide range of quality. Trends among the data yield clues regarding the cause of the observed isotopic fractionation. White wines, and wines generally perceived to be of lower quality, have lower δ 44/40Ca values compared to red wines and wines of generally perceived higher quality. Quality was assessed qualitatively through sensory evaluation, price, and scores assigned by critics. The relationship between δ 44/40Ca and wine quality was most apparent when comparing wines of one varietal from one producer from the same growing region. In the vineyard, wine quality is related to factors such as the tonnage of the crop and the ripeness of the grapes at the time of harvesting, the thickness of the skins for reds, the age of the vines, as well as the place where the grapes were grown (terroir). Quality is also influenced by winemaking practices such as fermentation temperature, duration of skin contact, and barrel ageing. Accordingly, the relationship between δ 44/40Ca and wine quality may originate during grape ripening in the vineyard or during winemaking in the cellar. We tested the grape ripening hypothesis using Merlot grapes sampled from a vineyard in the Okanagan, British Columbia, using sugar content (degrees Brix) as an indicator of ripeness. The grapes were separated into pulp, skin, and pip fractions and were analyzed separately. Thus far, there is no clear evidence for a systematic change in δ 44/40Ca values associated with progressive ripening of grapes in the vineyard. On the day of harvesting, the δ 44/40Ca value of juice squeezed from

  6. Correlated optical and isotopic nanoscopy

    Science.gov (United States)

    Saka, Sinem K.; Vogts, Angela; Kröhnert, Katharina; Hillion, François; Rizzoli, Silvio O.; Wessels, Johannes T.

    2014-04-01

    The isotopic composition of different materials can be imaged by secondary ion mass spectrometry. In biology, this method is mainly used to study cellular metabolism and turnover, by pulsing the cells with marker molecules such as amino acids labelled with stable isotopes (15N, 13C). The incorporation of the markers is then imaged with a lateral resolution that can surpass 100 nm. However, secondary ion mass spectrometry cannot identify specific subcellular structures like organelles, and needs to be correlated with a second technique, such as fluorescence imaging. Here, we present a method based on stimulated emission depletion microscopy that provides correlated optical and isotopic nanoscopy (COIN) images. We use this approach to study the protein turnover in different organelles from cultured hippocampal neurons. Correlated optical and isotopic nanoscopy can be applied to a variety of biological samples, and should therefore enable the investigation of the isotopic composition of many organelles and subcellular structures.

  7. Stable isotope enrichment: Current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities

  8. Stable isotope enrichment - current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1993-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities. (orig.)

  9. Lasers for isotope separation

    International Nuclear Information System (INIS)

    O'Hair, E.A.; Piltch, M.S.

    1976-01-01

    The Los Alamos Scientific Laboratory is conducting research on uranium enrichment. All processes being studied employ uranium molecules and use lasers to provide isotopic selectivity and enrichment. There are four well-defined infrared frequencies and two ultraviolet frequency bands of interest. The infrared frequencies are outside the range of the available lasers and an extensive research and development activity is currently underway. Lasers are available in the uv bands, however, much development work remains. The specification for the commercial uranium enrichment plant lasers will depend upon the results of the current enrichment experiments, the laser capital cost, reliability, and maintenance cost. For the processes under investigation there are specific photon requirements but latitude in how these requirements can be met. The final laser selections for the pilot plant need not be made until the mid-1980's. Between now and that time as extensive as possible a research and development effort will be maintained

  10. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Gregg, C.T.

    1977-01-01

    Clinical applications include the galactose breath test which consists of oral administration of 13 C-labeled galactose and measurement of the 13 C content of respired CO 2 as a function of time in patients with cirrhotic livers for diagnosis of liver dysfunction. Another application was the breath test to study glucose metabolism in children. Respired 13 CO 2 from ingested glucose- 13 C was measured for normal and diabetic children. Studies on mice in which 60 percent of the body carbon was replaced with 13 C failed to show significant effects of the isotope. Studies on biochemical applications include nuclear magnetic resonance studies of 13 C-labeled amino acids from Chlorella pyrenoidosa; studies on 15 N nmr spectra of arginine-guanidino- 13 C-2,3-- 15 N 2 as a function of pH; and isolation of fatty acids from algae

  11. Galilei-isotopic relativities

    International Nuclear Information System (INIS)

    Santilli, R.M.

    1991-09-01

    In this note we further develop the proposal made in preceding works of constructing the infinite family of Lie-isotopic liftings of Galilei's relativity for closed-isolated systems of particles possessing local, potential and selfadjoint, as well as nonlocal, nonhamiltonian and non selfadjoint internal forces. In particular, we show that the nonlinear and nonlocal generalization of the Galilei transformations introduced in a preceding note do indeed represent motion of extended particles within resistive media, but in such a way to coincide with the conventional transformations at the abstract, realization-free level. This allows the preservation of the basic, physical and mathematical axioms of Galilei's relativity under our liftings, and their realization in the most general possible nonlinear, nonlocal and nonhamiltonian way. (author). 18 refs, 1 fig

  12. Stable-isotope paleoclimatology

    International Nuclear Information System (INIS)

    Deuser, W.G.

    1978-01-01

    Seasonal variations of temperature and salinity in the surface waters of large parts of the oceans are well established. Available data on seasonal distributions of planktonic foraminifera show that the abundances of different species groups peak at different times of the year with an apparent succession of abundance peaks through most of the year. This evidence suggests that a measure of seasonal contrast is recorded in the isotope ratios of oxygen, and perhaps carbon, in the tests of different foraminiferal species. The evaluation of this potential paleoclimatologic tool awaits planned experiments with recent foraminifera in well-known settings, but a variety of available data is consistent with the idea that interspecies differences in 18 O content contain a seasonal component.(auth.)

  13. Container for hydrogen isotopes

    International Nuclear Information System (INIS)

    Solomon, D.E.

    1977-01-01

    A container for the storage, shipping and dispensing of hydrogen isotopes such as hydrogen, deuterium, tritium, or mixtures of the same which has compactness, which is safe against fracture or accident, and which is reusable is described. The container consists of an outer housing with suitable inlet and outlet openings and electrical feed elements, the housing containing an activated sorber material in the form, for example, of titanium sponge or an activated zirconium aluminate cartridge. The gas to be stored is introduced into the chamber under conditions of heat and vacuum and will be retained in the sorber material. Subsequently, it may be released by heating the unit to drive off the stored gas at desired rates

  14. Radio-isotopic tracers

    International Nuclear Information System (INIS)

    Wolfangel, R.G.

    1976-01-01

    The invention concerns the dispersions that may be used for preparing radio-isotopic tracers, technetium labelled dispersions, processes for preparing these dispersions and their use as tracers. Technetium 99m sulphur colloids are utilized as scintillation tracers to give a picture of the reticulo-endothelial system, particularly the liver and spleen. A dispersion is provided which only requires the addition of a radioactive nuclide to form a radioactively labelled dispersion that can be injected as a tracer. It is formed of a colloid of tin sulphur dispersed in an aqueous buffer solution. Such a reagent has the advantage of being safe and reliable and is easier to use. The colloid can be prepared more quickly since additions of several different reagents are avoided. There is no need to heat up and no sulphuretted hydrogen, which is a toxic gas, is used [fr

  15. Isotopically labelled benzodiazepines

    International Nuclear Information System (INIS)

    Liebman, A.A.

    1987-01-01

    This paper reports on the benzodiazepines which are a class of therapeutic agents. Improvements in the analytical methodology in the areas of biochemistry and pharmacology were significant, particularly in the application of chromatographic and spectroscopic techniques. In addition, the discovery and subsequent development of tritium and carbon-14 as an analytical tool in the biological sciences were essentially post-world war II phenomena. Thus, as these new chemical entities were found to be biologically active, they could be prepared in labeled form for metabolic study, biological half-life determination (pharmacokinetics), tissue distribution study, etc. This use of tracer methodology has been liberally applied to the benzodiazepines and also more recently to the study of receptor-ligand interactions, in which tritium, carbon-11 or fluorine-18 isotopes have been used. The history of benzodiazepines as medicinal agents is indeed an interesting one; an integral part of that history is their use in just about every conceivable labeled form

  16. Canada's isotope crisis : what next?

    International Nuclear Information System (INIS)

    Nathwani, J.; Wallace, D.

    2010-01-01

    Canada urgently requires a rigorous debate on the strategic options for ensuring a robust, reliable, and affordable supply of radioactive isotopes. Should the debate be confined to how Canada can best develop the necessary technologies solely for our own use or should Canada abandon the idea of producing its own isotope supply and any future aspirations to serve the global market? Canada's Isotope Crisis focuses on the central policy question: do we dare to try to shape the future or do we retreat into silence because we are not prepared to make the necessary investments for the future well-being of Canadians? This volume showcases pointed essays and analysis from members of the academy and individuals who have made contributions to the development of medical isotopes and pioneered their use in medical practice. It also includes commentary from those involved in the production, manufacturing, processing, and distribution of isotopes. Canada's Isotope Crisis is a multi-disciplinary effort that addresses the global dimension of isotope supply and combines expert opinions on the present and past with knowledge of the relevant government agencies and the basis for their decisions at critical junctures.

  17. Isotopically labelled pyrimidines and purines

    International Nuclear Information System (INIS)

    Balaban, A.T.; Bally, I.

    1987-01-01

    Among the three diazines, pyrimidine is by far the most important one because its derivatives uracil, thymine and cytosine are constituents of the ubiquitous deoxynucleic acids (DNA) and ribonucleic acids (RNA). Other derivatives of pyrimidine without condensed rings include barbiturates, alloxan, orotic acid and thiamine or vitamin B 1 . From the polycyclic derivatives of pyrimidine such as pteridine, alloxazine, and purine, the latter, through its derivatives adenine and guanine complete the list of bases which occur in DNA and RNA: in addition, other purine derivatives such as hypoxanthine, xanthine, theobromine, theophylline, caffeine and uric acid are important natural products with biological activity. The paper presents methods for preparing isotopically labeled pyrimidines as well as purine derivatives. For convenience, the authors describe separately carbon-labeled with radioisotopes 11 C (T 1/2 = 20.3 min) and 14 C (T 1/2 = 5736 years) or the stable isotope 13 C (natural abundance 1.1%) and then hydrogen-labeled systems with the radioisotope 3 H ≡ T (T 1/2 = 12.346 years) or with the stable isotope 2 H ≡ D (natural abundance 0.015%). We do not separate stable from radioactive isotopes because the synthetic methods are identical for the same element; however, the introduction of hydrogen isotopes into organic molecules is often performed by reactions such as isotope exchange which cannot take place in the case of carbon isotopes

  18. Isotopic shift in even-even barium isotopes

    International Nuclear Information System (INIS)

    Karim, Afaque; Naz, Tabassum; Ahmad, Shakeb

    2017-01-01

    We have discussed the correlation between a nuclear shape and its matter distribution. Here, we present the root-mean-square radii (r rms ) and rms charge radius (r ch ). We have also discussed the isotopic shift in terms of the observable ‹Δr 2 c › N,82 and its differential ‹Δr 2 c › N-2,N . We present nuclear radii evaluated using different interactions. Neutron radii and charge radii for all the isotopic chains are shown. Neutron radii for Ba isotopes show an increasing trend with the neutron number for all isotopic chains. One can observe a clear kink about magic number N=82

  19. Stable isotope genealogy of meteorites

    International Nuclear Information System (INIS)

    Pillinger, C.T.

    1988-01-01

    One of the oldest problems in meteoritics is that of taxonomically grouping samples. In recent years the use of isotopes, particularly oxygen isotopes has proved very successful in this respect. Other light-element systematics potentially can perform the same function. For example, nitrogen in iron meteorites, and nitrogen and carbon in ureilites and SNC meteorites. These measurements will serve to extend and augment existing classification schemes and provide clues to the nature of meteorite parent bodies. They can also aid in the recognition of the isotopic signatures relating to inaccessible regions of the Earth. (author)

  20. Compelling Research Opportunities using Isotopes

    International Nuclear Information System (INIS)

    2009-01-01

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1) medicine

  1. Advances in laser isotope separation

    International Nuclear Information System (INIS)

    Herman, I.P.; Bernhardt, A.F.

    1988-01-01

    The physical and chemical concepts required to understand laser isotope separation are presented and discussed. The numerous successful demonstrations of separating isotopes using lasers are reviewed to 1983. Emphasis is placed on the separation of 235-U from 238-U by multi-step selective ioniation of uranium atomic vapor, and on the separation of D and H and of T from D, by pulsed infrared laser multiple-photon dissociation of fluoroform and chloroform, respectively, because they are among the most successful and important examples of laser isotope separation to date. 161 refs.; 7 figs

  2. Isotope Exchange in Oxide Catalyst

    Science.gov (United States)

    Hess, Robert V.; Miller, Irvin M.; Schryer, David R.; Sidney, Barry D.; Wood, George M., Jr.; Hoyt, Ronald F.; Upchurch, Billy T.; Brown, Kenneth G.

    1987-01-01

    Replacement technique maintains level of CO2/18 in closed-cycle CO2 lasers. High-energy, pulsed CO2 lasers using rare chemical isotopes must be operated in closed cycles to conserve gas. Rare isotopes operated in closed cycles to conserve gas. Rare isotopes as CO2/18 used for improved transmission of laser beam in atmosphere. To maintain laser power, CO2 must be regenerated, and O2 concentration kept below few tenths of percent. Conditions achieved by recombining CO and O2.

  3. Stable isotopes - separation and application

    International Nuclear Information System (INIS)

    Lockhart, I.M.

    1980-01-01

    In this review, methods used for the separation of stable isotopes ( 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 34 S) will be described. The synthesis of labelled compounds, techniques for detection and assay, and areas of application will also be discussed. Particular attention will be paid to the isotopes of carbon, nitrogen, and oxygen; to date, sulphur isotopes have only assumed a minor role. The field of deuterium chemistry is too extensive for adequate treatment; it will therefore be essentially excluded. (author)

  4. Iodine isotopes and radiation safety

    International Nuclear Information System (INIS)

    Styro, B.; Nedvekajte, T.; Filistovich, V.

    1992-01-01

    Methods of concentration determination of stable and radioactive iodine isotopes in the Earth's different geospheres are described. Iodine isotopes concentration data, chemical forms and transformations as well as their exchange among separate geospheres of their global biochemical circulation (ocean, atmosphere, lithosphere and biosphere) are presented. Information on iodine isotopes as after-effects of nuclear installations accident (in particular, the Chernobyl accident) is generalized. The book is intended for scientists and practical workers in ecology and radioactivity protection and for a students of physics. 442 refs.; 82 figs.; 36 tabs

  5. Compelling Research Opportunities using Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-04-23

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1

  6. Neodymium isotopic variations in seawater

    Science.gov (United States)

    Piepgras, D. J.; Wasserburg, G. J.

    1980-01-01

    Direct measurement of the isotopic composition of Nd in the Atlantic agree with the Nd content in ferromanganese sediments and differ from the observed amounts in the Pacific samples. These data indicate the existence of distinctive differences in the isotopic composition of Nd in the waters of major oceans; the average values determined from seawater and ferromanganese sediments are considerably lower than in sources with oceanic mantle affinities showing that the REE in the oceans is dominated by continental sources. The Nd isotopic variations in seawater are applied to relate the residence time of Nd and mixing rates between the oceans.

  7. General physical fundamentals of isotope hydrology

    International Nuclear Information System (INIS)

    Moser, H.; Rauert, W.

    1976-01-01

    A description is given of the measurement and measuring units of stable isotopes, the physical properties, measurement and measuring units of radioactive isotopes, the fundamentals of the tracer technique, the environmental isotope distribution in the hydrosphere and the radiation protection in isotope hydrological investigations. (HK) [de

  8. Raman scattering method and apparatus for measuring isotope ratios and isotopic abundances

    International Nuclear Information System (INIS)

    Harney, R.C.; Bloom, S.D.

    1978-01-01

    Raman scattering is used to measure isotope ratios and/or isotopic abundances. A beam of quasi-monochromatic photons is directed onto the sample to be analyzed, and the resulting Raman-scattered photons are detected and counted for each isotopic species of interest. These photon counts are treated mathematically to yield the desired isotope ratios or isotopic abundances

  9. Isotopic Changes During Digestion: Protein

    Science.gov (United States)

    Tuross, N.

    2013-12-01

    Nutrient and hydrological inputs traverse a complicated route of pH, enzymatic and cellular processes in digestion in higher animals. The end products of digestion are the starting products for biosynthesis that are often used to interpret past life-ways. Using an artificial gut system, the isotopic changes (dD, d18O, d13C and d15N) of protein are documented. Three separate protein sources are subjected to the conditions, chemical and enzymatic, found in the stomach and upper small intestine with only a small shift in the oxygen isotopic composition of the proteins observed. Middle to lower small intestine parameters produced both greater isotopic effects and significantly lower molecular weight products. The role of the gastric enterocyte and the likely involvement of the internal milieu of this cell in the isotopic composition of amino acids that are transported to the liver are reported.

  10. High atomic weight isotope separator

    International Nuclear Information System (INIS)

    Book, D.L.

    1978-01-01

    A continuously operating device is described which separates one isotopic species of a given element from a mixture. The given element is vaporized and formed into a neutral beam containing the isotopes desired to be separated. The plasma is accelerated through a laser beam which is formed by two separate lasers which operate in the continuous wave mode in which the beams are as nearly as possible in the same beam path. The two laser output beams excite and ionize the isotope of interest while leaving the remaining atoms unaffected. The ionized isotopes are then separated from the beam by an electrostatic deflection technique and the unaffected atoms continue on in their path and are directed to a recovery device

  11. Discoveries of isotopes by fission

    Indian Academy of Sciences (India)

    country of discovery as well as the production mechanism used to produce the isotopes. ... the disintegration products of bombarded uranium, as a consequence of a ..... advanced accelerator and newly developed separation and detection ...

  12. Isotope separation by standing waves

    International Nuclear Information System (INIS)

    Altshuler, S.

    1984-01-01

    The separation of isotopes is accomplished by scattering a beam of particles from a standing electromagnetic wave. The particles may consist of either atoms or molecules, the beam having in either case a desired isotope and at least one other. The particle beam is directed so as to impinge on the standing electromagnetic wave, which may be a light wave. The particles, that is, the atomic or molecular quantum-mechanical waves, see basically a diffraction grating corresponding to the troughs and peaks of the electromagnetic wave. The frequency of the standing electromagnetic wave substantially corresponds to an internal energy level-transition of the desired isotope. Accordingly, the desired isotope is spatially separated by being scattered or diffracted. (author)

  13. Isotope analysis in petroleum exploration

    International Nuclear Information System (INIS)

    Rodrigues, R.

    1982-01-01

    The study about isotopic analysis in petroleum exploration performed at Petrobras Research Center is showed. The results of the petroleum recuperation in same Brazilian basin and shelves are comented. (L.H.L.L.) [pt

  14. Isotope-based quantum information

    CERN Document Server

    G Plekhanov, Vladimir

    2012-01-01

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial...

  15. Isotope shifts in unstable nuclei

    International Nuclear Information System (INIS)

    Rebel, H.

    1980-05-01

    Current experimental investigations of isotope shifts in atomic spectra of unstable nuclei and the resulting information about size and shape of nuclei far off stability are discussed with reference to some representative examples. (orig.)

  16. Dielectrophoretic separation of gaseous isotopes

    International Nuclear Information System (INIS)

    McConnell, D.B.

    1976-01-01

    This invention relates to a process for the separation of gaseous isotopes by electrophoresis assisted by convective countercurrent flow and to an apparatus for use in the process. The invention is especially applicable to heavy water separation from steam; however, it is to be understood that the invention is broadly applicable to the separation of gaseous isotopes having different dipole moments and/or different molecular weights. (author)

  17. Isotope effects in photochemical rearrangements

    International Nuclear Information System (INIS)

    Sommer, F.

    1983-01-01

    Taking anthracene resp. 9-deuteroanthracene as the initial substance, different substitution products have been prepared. The products originating by direct photolysis have been characterized and their structure has been determined. By comparing the measured kinetic isotope effect and the quantum yield of the nondeuterated and the monodeuterated fluorenes formed it could been demonstrated that the isotope effect mainly is due to the reaction rates and the influence of the deuterium substitution upon the radiationless desactivation against that is small. (HBR) [de

  18. Isotope studies in brain diseases

    Energy Technology Data Exchange (ETDEWEB)

    Silfverskioeld, B [Department of Neurology, Soedersjukhuset, S-100 64 Stockholm (Sweden)

    1978-09-01

    Serial pictures of cerebral isotope flow and accumulation after intravenous injection provide several kinds of valuable diagnostic information. The reliability can be increased by using computer-processed pictures on a TV screen and by numerical analysis in accordance with paritcular programs constructed for our routine work. An isotope study should be done when computerized transmission tomography scans have failed to provide a conclusive diagnosis. It should then be performed with optimal technique in order to reduce the need of angiograms.

  19. Isotopes and radiations in agriculture

    International Nuclear Information System (INIS)

    Sawant, A.G.

    1998-01-01

    Some of the spectacular advances in agriculture in developing nations have stimulated wide interest both in basic as well as adaptive research and in harnessing all the tools that science can offer for progress of agriculture. The nuclear tools are relevant in this respect and also offer particular promise in some areas. Ionising radiations and isotopes have immense applications in agriculture. Both radioisotopes and stable isotopes are being used

  20. Phonon scattering by isotopic impurities

    International Nuclear Information System (INIS)

    Dacol, D.K.

    1974-06-01

    The effects upon vibrations of a perfect crystal lattice due to the replacement of some of its atoms by isotopes of these atoms are studied. The approach consists in considering the isotopic impurities as scattering centres for the quanta of the elastic waves the objective is to obtain the scattering amplitudes. These amplitudes are obtained through a canonical transformation method which was introduced by Chevalier and Rideau in the study of the Wentzel's model in quantum field theory

  1. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  2. Isotopic study of Karst water

    International Nuclear Information System (INIS)

    Leskovsek-Sefman, H.

    1985-01-01

    Measurement of the isotopic composition of water formed part of an extended investigation of the water drainage system in the Slovenian Karst. These studies were planned to complement geological and speleological investigations which are already being performed in this area, with the knowledge of the mechanism of changes in the isotopic composition of water in the natural environment on some smaller locations, Planina cave near Postojna where the vertical percolation of meteoric water through the karstified carbonate ceiling was studied and the water catchment areas of some small rivers, Ljubljanica, Rizana and Idrijca. Mass spectrometric investigations of the isotopic composition of some elements ( 18 O, D, 13 C and T) in water and in dissolved carbonates, as well as the isotopic composition of 18 O and 13 C in cave carbonates were performed. The results allow to conclude that the waters in karst aquifers in spite of producing the homogenisation to a great extent, qualitative determination of the retention time and of the prevailing sources for some springs and surface and underground water flows is nevertheless possible. The isotopic composition of 18 O in water and of 18 O and 13 C in dissolved carbonates depends on climatic conditions and on denudation processes. The investigation of cave carbonates revealed that they have different isotopic compositions of 18 O and 13 C because of different locations and also different ages

  3. Isotopic meteoric line for Colombia

    International Nuclear Information System (INIS)

    Rodriguez N, Cesar O

    2004-01-01

    Isotope analyses from representative rainfall samples taken from different areas in Colombia were processed to yield the meteoric line. Stable isotope composition in precipitation reflects the effects of temperature, altitude and of the continental site, being affected by different sources of atmospheric humidity over the Colombian territory. There is a seasonal variation in isotopic composition of precipitation with grater σ deviation during the rainy season and lower values in the dry season. In coastal areas the variation is smaller and is more pronounced than at continental stations. Correlation between altitude and isotope content led to equations, which indicate, on a regional level, a change in isotopic composition with altitude, of about 0.5 σ units per 200 m, for O 18 and 4 σ units per 200 m for H 2 . Such equations may be used to identify the original altitude of precipitation water, in hydrological surface and groundwater studies. Meteoric line and the concepts derived from the resulting equations presented in this paper may be applied to the interpretation of isotope analysis in future hydrological studies, particularly in areas without available data

  4. Isotope-based quantum information

    International Nuclear Information System (INIS)

    Plekhanov, Vladimir G.

    2012-01-01

    The present book provides to the main ideas and techniques of the rapid progressing field of quantum information and quantum computation using isotope - mixed materials. It starts with an introduction to the isotope physics and then describes of the isotope - based quantum information and quantum computation. The ability to manipulate and control electron and/or nucleus spin in semiconductor devices provides a new route to expand the capabilities of inorganic semiconductor-based electronics and to design innovative devices with potential application in quantum computing. One of the major challenges towards these objectives is to develop semiconductor-based systems and architectures in which the spatial distribution of spins and their properties can be controlled. For instance, to eliminate electron spin decoherence resulting from hyperfine interaction due to nuclear spin background, isotopically controlled devices are needed (i.e., nuclear spin-depleted). In other emerging concepts, the control of the spatial distribution of isotopes with nuclear spins is a prerequisite to implement the quantum bits (or qbits). Therefore, stable semiconductor isotopes are important elements in the development of solid-state quantum information. There are not only different algorithms of quantum computation discussed but also the different models of quantum computers are presented. With numerous illustrations this small book is of great interest for undergraduate students taking courses in mesoscopic physics or nanoelectronics as well as quantum information, and academic and industrial researches working in this field.

  5. Isotope separation apparatus and method

    International Nuclear Information System (INIS)

    Feldman, B. J.

    1985-01-01

    The invention relates to an improved method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferably substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. Because the molecules in the beam occupy various degenerate energy levels, if the laser beam comprises chirped pulses comprising selected wavelengths, the laser beam will very efficiently excite substantially all unexcited molecules and will cause stimulated emission of substantially all excited molecules of a selected one of the isotopes in the beam which such pulses encounter. Excitation caused by first direction chirped pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning chirped pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement of essentially all the molecules containing the one isotope is accomplished by a large number of chirped pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam

  6. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    Ehrfeld, W.; Ehrfeld, U.

    1977-01-01

    In the nuclear fuel cycle, uranium enrichment is not a principal problem of technological feasibility. Several processes exist for producing LWR fuel and the enrichment method can be selected in consideration of economical, environmental, and political aspects. To date, the gaseous diffusion process constitutes the major part of enrichment capacity. This process has been well demonstrated for over 30 years and, as a matter of fact, no major technological and economical progress is to be expected in the future. Because of their comparatively high development potential, the centrifuge and the separation nozzle method may become increasingly favorable in economics. The development of the centrifuge process which is superior by its low specific energy consumption aims at technological improvements. In the separation nozzle process which offers the advantage of a comparatively simple technology a further reduction of the specific energy consumption is to be expected because of the thermodynamically favorable separation mechanism of this process. Laser isotope separation methods are still on the laboratory scale, although large financial funds have been spent. (orig.) [de

  7. Insects, isotopes and radiations

    International Nuclear Information System (INIS)

    Lingkvist, D.A.

    1987-01-01

    The IAEA activity on coordinating the IAEA member-state efforts in the field of pest control is considered. A complex program of agricultural pest control (IPM), applied in many parts of the world is developed. The program provides for the use of natural means of control and cases of critical pest numbers-the use of insecticides. When controlling certain types of insects it is advisable to apply the 'large area control' methods which provide for the insect destruction in places of their concentration prior to migration. Methods of pest control over large areas also include radiation sexual sterilization method (SSM), application of insect phoromons (sexual attractants) to prevent mating, other types of chemical attractants, traps, mass cultivation and reproduction of parasite plants and animals, destroying insects, as well as improvement of host-plant resistance. A great attention is paid to isotope and radiation application in pest control (labelling, sexual sterilization using ionising radiation, radiation application in genetic engineering, mutant plant cultivation)

  8. Hydrogen isotope technology

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Hydrogen pumping speeds on panels of molecular sieve types 5A and Na-Y were compared for a variety of sieve (and chevron) temperatures between 10 and 30 K. Although pumping speeds declined with time, probably because of the slow diffusion of hydrogen from the surface of the sieve crystals into the internal regions, the different sieve materials and operating conditions could be compared using time-averaged pump speeds. The (average) pumping speeds declined with increasing temperature. Under some conditions, the Na-Y sieve performed much better than the 5A sieve. Studies of the effect of small concentrations (approx. 4%) of hydrogen on helium pumping indicate that compound cryopumps in fusion reactors will not have to provide complete screening of hydrogen from helium panels. The concentrations of hydrogen did not lower effective helium pumping speeds or shorten the helium operating period between instabilities. Studies of tritium recovery from blankets of liquid lithium focused on design and construction of a flowing-lithium test system and on ultimate removal of tritium from yttrium sorbents. At 505 0 C, tritium release from yttrium behaves as a diffusion-controlled process, but the release rates are very low. Apparently, higher temperatures will be required for effective sorbent regeneration. An innovative technique for separating hydrogen isotopes by using bipolar electrolysis with permeable electrodes was analyzed to determine its potential usefulness in multistage separation

  9. Electron linac for medical isotope production with improved energy efficiency and isotope recovery

    Science.gov (United States)

    Noonan, John; Walters, Dean; Virgo, Matt; Lewellen, John

    2015-09-08

    A method and isotope linac system are provided for producing radio-isotopes and for recovering isotopes. The isotope linac is an energy recovery linac (ERL) with an electron beam being transmitted through an isotope-producing target. The electron beam energy is recollected and re-injected into an accelerating structure. The ERL provides improved efficiency with reduced power requirements and provides improved thermal management of an isotope target and an electron-to-x-ray converter.

  10. Calcium Isotope Analysis by Mass Spectrometry

    Science.gov (United States)

    Boulyga, S.; Richter, S.

    2010-12-01

    The variations in the isotopic composition of calcium caused by fractionation in heterogeneous systems and by nuclear reactions can provide insight into numerous biological, geological, and cosmic processes, and therefore isotopic analysis finds a wide spectrum of applications in cosmo- and geochemistry, paleoclimatic, nutritional, and biomedical studies. The measurement of calcium isotopic abundances in natural samples has challenged the analysts for more than three decades. Practically all Ca isotopes suffer from significant isobaric interferences, whereas low-abundant isotopes can be particularly affected by neighboring major isotopes. The extent of natural variations of stable isotopes appears to be relatively limited, and highly precise techniques are required to resolve isotopic effects. Isotope fractionation during sample preparation and measurements and instrumental mass bias can significantly exceed small isotope abundance variations in samples, which have to be investigated. Not surprisingly, a TIMS procedure developed by Russell et al. (Russell et al., 1978. Geochim Cosmochim Acta 42: 1075-1090) for Ca isotope measurements was considered as revolutionary for isotopic measurements in general, and that approach is used nowadays (with small modifications) for practically all isotopic systems and with different mass spectrometric techniques. Nevertheless, despite several decades of calcium research and corresponding development of mass spectrometers, the available precision and accuracy is still not always sufficient to achieve the challenging goals. This presentation discusses figures of merits of presently used analytical methods and instrumentation, and attempts to critically assess their limitations. Additionally, the availability of Ca isotope reference materials will be discussed.

  11. ITER isotope separation system

    International Nuclear Information System (INIS)

    Busigin, A.; Sood, S.K.; Kveton, O.K.; Sherman, R.H.; Anderson, J.L.

    1990-09-01

    This document presents the results of a study that examined the technical operating and economic viability of an alternative Isotope Separation System (ISS) design based on the distributed design concept. In the distributed design, the ISS is broken up into local independently operable subsystems matched to local processing requirements. The distributed design accepts the same feeds and produces essentially the same products as the reference design. The distributed design consists of two separate, independent subsystems. The first, called ISS-H, receives only protium-dominated streams and waste water from tritium extraction. It has two cryogenic distillation columns and can produce a 50 percent D, 50 percent T product since it lacks D/T separation capability. A final 80 percent T 2 concentration product can be obtained by blending the 50 percent T 2 stream from ISS-H with the more than 99 percent T 2 stream from the second subsystem, ISS-D. The second subsystem receives only deuterium-dominated feeds, which also contain some protium. ISS-D is as complex as the reference design, but smaller. Although each subsystem has some advantages, such as only two cryogenic distillation columns in ISS-H and better than 99 percent steady state T 2 product in ISS-D, the combined subsystems do not offer any real advantage compared to the reference IISS. The entire distributed ISS design has been simulated using Ontario Hydro's FLOSHEET steady state process simulator. Dynamic analysis has not been done for the distributed design. (10 refs., 3 figs., 8 tabs.)

  12. Development of isotope hydrology technology in China

    International Nuclear Information System (INIS)

    Li Zhangsu

    1988-01-01

    The development of isotope hydrology technology in China is described. The isotope technology provides an independent approach for solving hydrological problems. Isotope hydrology is applied in three ways: the use of change in environmental isotopic composition of water (especially used in water resources exploitation), the use of artificial radioactive tracers and the use of redioisotope instruments. Many important achievements have been obtained in application of isotopic hydrology technology. For the sake of promoting rapid development of isotope hydrology the topics on management, technology and others are commented

  13. Ca isotopes in refractory inclusions

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.

    1984-01-01

    We report measurements of the absolute isotope abundance of Ca in Ca-Al-rich inclusions from the Allende and Leoville meteorites. Improved high precision measurements are reported also for 46 Ca. We find that nonlinear isotope effects in Ca are extremely rare in these inclusions. The absence of nonlinear effects in Ca, except for the effects in FUN inclusions, is in sharp contrast to the endemic effects in Ti. One fine-grained inclusion shows an excess of 46 Ca of (7 +- 1) per mille, which is consistent with addition of only 46 Ca or of an exotic (*) component with 46 Ca* approx. 48 Ca*. FUN inclusion EK-1-4-1 shows a small 46 Ca excess of (3.3 +- 1.0) per mille; this confirms that the exotic Ca components in EK-1-4-1 were even more deficient in 46 Ca relative to 48 Ca than is the case for normal Ca. The Ca in the Ca-Al-rich inclusions shows mass dependent isotope fractionation effects which have a range from -3.8 to +6.7 per mille per mass unit difference. This range is a factor of 20 wider than the range previously established for bulk meteorites and for terrestrial and lunar samples. Ca and Mg isotope fractionation effects in the Ca-Al-rich inclusions are common and attributed to kinetic isotope effects. (author)

  14. Handbook of environmental isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Baskaran, Mark (ed.) [Wayne State Univ., Detroit, MI (United States). Dept. Geology

    2011-07-01

    Applications of radioactive and stable isotopes have revolutionized our understanding of the Earth and near-earth surface processes. The utility of the isotopes are ever-increasing and our sole focus is to bring out the applications of these isotopes as tracers and chronometers to a wider audience so that they can be used as powerful tools to solve environmental problems. New developments in this field remain mostly in peer-reviewed journal articles and hence our goal is to synthesize these findings for easy reference for students, faculty, regulators in governmental and non-governmental agencies, and environmental companies. While this volume maintains its rigor in terms of its depth of knowledge and quantitative information, it contains the breadth needed for wide variety problems and applications in the environmental sciences. This volume presents all of the newer and older applications of isotopes pertaining to the environmental problems in one place that is readily accessible to readers. This book not only has the depth and rigor that is needed for academia, but it has the breadth and case studies to illustrate the utility of the isotopes in a wide variety of environments (atmosphere, oceans, lakes, rivers and streams, terrestrial environments, and sub-surface environments) and serves a large audience, from students and researchers, regulators in federal, state and local governments, and environmental companies. (orig.)

  15. Isotope separation apparatus and method

    International Nuclear Information System (INIS)

    Cotter, T.P.

    1982-01-01

    The invention relates to a method and apparatus for laser isotope separation by photodeflection. A molecular beam comprising at least two isotopes to be separated intersects, preferable substantially perpendicular to one broad side of the molecular beam, with a laser beam traveling in a first direction. The laser beam is reflected back through the molecular beam, preferably in a second direction essentially opposite to the first direction. The laser beam comprises pi-pulses of a selected wavelength which excite unexcited molecules, or cause stimulated emission of excited molecules of one of the isotopes. Excitation caused by first direction pi-pulses moves molecules of the isotope excited thereby in the first direction. Stimulated emission of excited molecules of the isotope is brought about by returning pi-pulses traveling in the second direction. Stimulated emission moves emitting molecules in a direction opposite to the photon emitted. Because emitted photons travel in the second direction, emitting molecules move in the first direction. Substantial molecular movement is accomplished by a large number of pi-pulse-molecule interactions. A beam corer collects the molecules in the resulting enriched divergent portions of the beam

  16. Isotope-equipped measuring instruments

    International Nuclear Information System (INIS)

    Miyagawa, Kazuo; Amano, Hiroshi

    1980-01-01

    In the steel industry, though the investment in isotope-equipped measuring instruments is small as compared with that in machinery, they play important role in the moisture measurement in sintering and blast furnaces, the thickness measurement in rolling process and others in automatic control systems. The economic aspect of the isotope-equipped measuring instruments is described on the basis of the practices in Kimitsu Works of Nippon Steel Corporation: distribution of such instruments, evaluation of economic effects, usefulness evaluation in view of raising the accuracy, and usefulness evaluation viewed from the failure of the isotope instruments. The evaluation of economic effects was made under the premise that the isotope-equipped measuring instruments are not employed. Then, the effects of raising the accuracy are evaluated for a γ-ray plate thickness gauge and a neutron moisture gauge for coke in a blast furnace. Finally, the usefulness was evaluated, assuming possible failure of the isotope-equipped measuring instruments. (J.P.N.)

  17. Isotopes a very short introduction

    CERN Document Server

    Ellam, Rob

    2016-01-01

    An isotope is a variant form of a chemical element, containing a different number of neutrons in its nucleus. Most elements exist as several isotopes. Many are stable while others are radioactive, and some may only exist fleetingly before decaying into other elements. In this Very Short Introduction, Rob Ellam explains how isotopes have proved enormously important across all the sciences and in archaeology. Radioactive isotopes may be familiar from their use in nuclear weapons, nuclear power, and in medicine, as well as in carbon dating. They have been central to establishing the age of the Earth and the origins of the solar system. Combining previous and new research, Ellam provides an overview of the nature of stable and radioactive isotopes, and considers their wide range of modern applications. ABOUT THE SERIES: The Very Short Introductions series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subjec...

  18. Retention of gaseous isotopes

    International Nuclear Information System (INIS)

    Yarbro, O.O.; Mailen, J.C.; Stephenson, M.J.

    1977-01-01

    difficult as the tritium combines and distributes with the water inventory throughout the plant. To avoid this, a high temperature (550 0 C) volatilation step, termed voloxidation, is being developed at ORNL which drives most (up to 99%) of the tritium out of the fuel and traps it prior to aqueous processing. Other processes for tritium control under study include total retention of water and isotopic separation of tritium from plant aqueous effluents. Carbon-14 is produced in oxide fuels primarily by n-p reactions with 14 N contaminant in the fuel. Little is known about the actual behavior of 14 C in a reprocessing plant, and most of the effort is directed toward identifying the chemical forms and process sources of the 14 C effluents

  19. Oak Ridge National Laboratory's isotope enrichment program

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.C.

    1997-01-01

    The Isotope Enrichment Program (IEP) at Oak Ridge National Laboratory (ORNL) is responsible for the production and distribution of ∼225 enriched stable isotopes from 50 multi-isotopic elements. In addition, ORNL distributes enriched actinide isotopes and provides extensive physical- and chemical-form processing of enriched isotopes to meet customer requirements. For more than 50 yr, ORNL has been a major provider of enriched isotopes and isotope-related services to research, medical, and industrial institutions throughout the world. Consolidation of the Isotope Distribution Office (IDO), the Isotope Research Materials Laboratory (IRML), and the stable isotope inventories in the Isotope Enrichment Facility (IEF) have improved operational efficiencies and customer services. Recent changes in the IEP have included adopting policies for long-term contracts, which offer program stability and pricing advantages for the customer, and prorated service charges, which greatly improve pricing to the small research users. The former U.S. Department of Energy (DOE) Loan Program has been converted to a lease program, which makes large-quantity or very expensive isotopes available for nondestructive research at a nominal cost. Current efforts are being pursued to improve and expand the isotope separation capabilities as well as the extensive chemical- and physical-form processing that now exists. The IEF's quality management system is ISO 9002 registered and accredited in the United States, Canada, and Europe

  20. Studying Antarctic Ordinary Chondrite (OC) and Miller Range (MIL) Nakhlite Meteorites to Assess Carbonate Formation on Earth and Mars

    Science.gov (United States)

    Evans, Michael Ellis

    Carbonates are found in meteorites collected from Antarctica. The stable isotope composition of these carbonates records their formation environment on either Earth or Mars. The first research objective of this dissertation is to characterize the delta18O and delta 13C values of terrestrial carbonates formed on Ordinary Chondrites (OCs) collected in regions near known martian meteorites. The second objective is to characterize the delta18O and delta13C values of martian carbonates from Nakhlites collected from the Miller Range (MIL). The third objective is to assess environmental changes on Mars since the Noachian period. The OCs selected had no pre-terrestrial carbonates so any carbonates detected are presumed terrestrial in origin. The study methodology is stepped extraction of CO2 created from phosphoric acid reaction with meteorite carbonate. Stable isotope results show that two distinct terrestrial carbonate species (Ca-rich and Fe/Mg-rich) formed in Antarctica on OCs from a thin-film of meltwater containing dissolved CO2. Carbon isotope data suggests the terrestrial carbonates formed in equilibrium with atmospheric CO2 delta 13C = -7.5‰ at >15°C. The wide variation in delta 18O suggests the carbonates did not form in equilibrium with meteoric water alone, but possibly formed from an exchange of oxygen isotopes in both water and dissolved CO2. Antarctica provides a model for carbonate formation in a low water/rock ratio, near 0°C environment like modern Mars. Nakhlite parent basalt formed on Mars 1.3 billion years ago and the meteorites were ejected by a single impact approximately 11 million years ago. They traveled thru space before eventually falling to the Earth surface 10,000-40,000 years ago. Nakhlite samples for this research were all collected from the Miller Range (MIL) in Antarctica. The Nakhlite stable isotope results show two carbonate species (Ca-rich and Fe/Mg-rich) with a range of delta18O values that are similar to the terrestrial OC

  1. Isotopic depletion with Monte Carlo

    International Nuclear Information System (INIS)

    Martin, W.R.; Rathkopf, J.A.

    1996-06-01

    This work considers a method to deplete isotopes during a time- dependent Monte Carlo simulation of an evolving system. The method is based on explicitly combining a conventional estimator for the scalar flux with the analytical solutions to the isotopic depletion equations. There are no auxiliary calculations; the method is an integral part of the Monte Carlo calculation. The method eliminates negative densities and reduces the variance in the estimates for the isotope densities, compared to existing methods. Moreover, existing methods are shown to be special cases of the general method described in this work, as they can be derived by combining a high variance estimator for the scalar flux with a low-order approximation to the analytical solution to the depletion equation

  2. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1986-08-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high-abundance, naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56. All requests for the loan of samples should be submitted with a summary of the purpose of the loan to: Iotope Distribution Office, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37831. Requests from non-DOE contractors and from foreign institutions require DOE approval

  3. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Krouse, H.R.

    1990-01-01

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  4. Lithium isotopic separation: preliminary studies

    International Nuclear Information System (INIS)

    Macedo, Sandra Helena Goulart de

    1998-01-01

    In order to get the separation of natural isotopes of lithium by electrolytic amalgamation, an electrolytic cell with a confined mercury cathode was used to obtain data for the design of a separation stage. The initial work was followed by the design of a moving mercury cathode electrolytic cell and three experiments with six batches stages were performed for the determination of the elementary separation factor. The value obtained, 1.053, was ill agreement: with the specialized literature. It was verified in all experiments that the lithium - 6 isotope concentrated in the amalgam phase and that the lithium - 7 isotope concentrated in the aqueous phase. A stainless-steel cathode for the decomposition of the lithium amalgam and the selective desamalgamation were also studied. In view of the results obtained, a five stages continuous scheme was proposed. (author)

  5. Shielding container for radioactive isotopes

    International Nuclear Information System (INIS)

    Sumi, Tetsuo; Tosa, Masayoshi; Hatogai, Tatsuaki.

    1975-01-01

    Object: To effect opening and closing bidirectional radiation used particularly for a gamma densimeter or the like by one operation. Structure: This device comprises a rotatable shielding body for receiving radioactive isotope in the central portion thereof and having at least two radiation openings through which radiation is taken out of the isotope, and a shielding container having openings corresponding to the first mentioned radiation openings, respectively. The radioactive isotope is secured to a rotational shaft of the shielding body, and the shielding body is rotated to register the openings of the shielding container with the openings of the shielding body or to shield the openings, thereby effecting radiation and cut off of gamma ray in the bidirection by one operation. (Kamimura, M.)

  6. Shape coexistence in selenium isotopes

    International Nuclear Information System (INIS)

    Liu Ying; Cao Zhongbin; Xu Furong

    2010-01-01

    Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)

  7. Isotopic composition of past precipitation

    International Nuclear Information System (INIS)

    Edwards, T.W.D.

    1998-01-01

    The distribution of stable isotopes in precipitation provides critical quantitative information about the global water cycle. The first PAGES/IAEA ISOMAP workshop was held at the IAEA headquarters in Vienna, 24-26 August 1998, which gathered 32 participants. The presentation and discussions demonstrated that a high level of sophistication already exists in the development of transfer functions between measured parameters and precipitation, as a result of the extensive use of water isotope tracers in paleo-environmental investigations, but a major challenge facing both producers and users of paleo-isotope data is the effective management of data and meta-data, to permit ready retrieval of raw and inferred data for comparison and reinterpretation. This will be in important goal of future ISOMAP activities. The critical need for more paleo-data from low latitudes was clearly recognized

  8. Isotopes in research and industry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1961-01-15

    A comprehensive review of the present state of the use of radioisotopes in the physical sciences and industry was made at a major international conference in Copenhagen from 6 to 16 September 1960. The conference covers the use of radioisotopes in geophysics, metallurgy, solid state physics and nuclear physics, industrial applications of radioisotopes, which were divided into two groups, namely applications based on the tracer function of isotopes and those based on the penetration, absorption or scattering of radiation, use of isotopes in various branches of chemistry - from analysis to determine extremely small amounts of material to a study of the mechanism of various chemical reactions.

  9. Electron scattering off palladium isotopes

    International Nuclear Information System (INIS)

    Laan, J.B. van der.

    1986-01-01

    The low-lying states of the even Pd isotopes are characterized by vibrator-like properties. In this thesis the results of an electron scattering experiment on the Pd isotopes, designed to study the description of such nuclei in the Anharmonic Vibrator Model (AVM) and the Interacting Boson Approximation (IBA), are presented and discussed. Data have been taken at the high-resolution electron scattering facility of NIKHEF-K and covered a momentum-transfer range of 0.4 to 2.5 fm -1 . (Auth.)

  10. Natural fractionation of uranium isotopes

    International Nuclear Information System (INIS)

    Noordmann, Janine

    2015-01-01

    The topic of this thesis was the investigation of U (n( 238 U) / n( 235 U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n( 238 U) and n( 235 U), on Earth.

  11. Separation process for boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, S D

    1975-06-12

    The method according to the invention is characterized by the steps of preparing a gaseous mixture of BCl/sub 3/ containing the isotopes of boron and oxygen as the extractor, irradiating that mixture in the tube of the separator device by means of P- or R-lines of a CO/sub 2/ laser for exciting the molecules containing a given isotope of boron, simultaneously irradiating the mixture with UV for photodissociating the excited BCl/sub 3/ molecules and separating BCl/sub 3/ from the reaction products of photodissociation and from oxygen. Such method is suitable for preparing boron used in nuclear reactors.

  12. Isotopic cisternography. Its clinical value

    International Nuclear Information System (INIS)

    Lemort, J.P.; Bizais, Y.; Herzog, B.

    1976-01-01

    A brief study of isotopic cisternography with a new tracer is performed. After describing the physiological circulation of the cerebrospinal fluid the different tracers used are studied and experience with 111 Indium DTPA which is tending to replace the other tracers is given. The indications and the normal and pathological results are discussed. The different forms of hydrocephalus are described; this examination makes it possible in particular to diagnose cases of hydrocephalus with normal pressure, cysts, or localized, subarachnoid pockets. Cerebrospinal fluid fistulas are detected by this technique. Finally, the place of isotopic cisternography in relation to the other neuroradiological examinations and in relation to tomodensitometric investigations is discussed [fr

  13. Recent development in isotope ratio mass spectrometry

    International Nuclear Information System (INIS)

    Platzner, I.

    1992-01-01

    Within the limited of this review the following topics will be briefly discussed: a) Accuracy, precision, internal relative standard deviation (RISD) and external relative standard deviation (RESD) of isotope ratio measurements. With advanced instrumentation and use of standard reference materials, high accuracy and RESD = 0.002% (or better) may be achieved; b) The advantages of modern automatic isotope ratio mass spectrometer are briefly described. Computer controlled operation and data acquisition, and multiple ion collection are the recent important improvement; c) The isotopic fractionation during the course of isotope ratio measurement is considered as a major source of errors in thermal ionization of metallic elements. The phenomenon in strontium, neodymium, uranium, lead and calcium and methods to correct the measured data are discussed; d) Applications of isotope ratio mass spectrometry in atomic weight determinations, the isotope dilution technique, isotope geology, and isotope effects in biological systems are described together with specific applications in various research and technology area. (author)

  14. Isotope separation using vibrationally excited molecules

    International Nuclear Information System (INIS)

    1979-01-01

    This invention relates to isotope separation employing isotopically selective vibrational excitation and vibration-translation reactions of the excited particles. Uranium enrichment, using uranium hexafluoride, is a particular embodiment. (U.K.)

  15. Isotope applications in the environmental field

    International Nuclear Information System (INIS)

    DeWitt, R.

    1978-01-01

    Established uses of enriched isotopes in the environmental field were surveyed to determine future trends in isotope needs. Based on established isotope uses, on the projected increase in the pollution problem, and on the apparent social and economic pressure for pollution abatement, a significant demand for enriched isotopes appears to be developing for the assessment and control of air, water, and soil pollutants. Isotopic techniques will be used in combination with conventional methods of detection and measurement, such as gas chromatography, x-ray fluorescence, and atomic absorption. Recent advances in economical isotope separation methods, instrumentation, and methodology promise to place isotopic technology within the reach of most research and industrial institutions. Increased application of isotope techniques appears most likely to occur in areas where data are needed to characterize the movement, behavior, and fate of pollutants in the environment

  16. High mass isotope separation process and arrangement

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1978-01-01

    An isotope separation arrangement for separating a preselected isotope from a mixture of chemically identical but isotopically different molecules by either photon-induced pure rovibrational or vibronic selective excitation of the molecules containing the atoms of the isotope to be separated from a lower to a higher energy state, and a chemical reaction of the higher energy state molecules with a chemically reactive agent to form a chemical compound containing primarily the atoms of isotope to be separated in a physicochemical state different from the physicochemical state of the mixture of chemically identical but isotopically different molecules. The chemical compound containing the atoms of the isotope to be separated may be subsequently processed to obtain the isotope

  17. Method and device for isotope separation

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1976-01-01

    The method works with a converted Q machine. The plasma containing the isotopes to be separated is crossed by a magnetic field running in the direction of the plasma column. More energy is transfered to the chosen isotope by oscillating magnetic and/or electric fields or by sound waves by using the specific resonance frequency for the selected isotope. The isotopes thus heated to different extents can be separated according to various methods given in the patent claims. (GG) [de

  18. Isotope mixtures of hydrogen in vanadium

    International Nuclear Information System (INIS)

    Mecking-Schloetensack, P.

    1982-03-01

    The properties of isotope-mixtures of Protium and Deuterium stored in Vanadium have been studied. Protium and Deuterium are existing as interstitial-atoms on tetrahedral sites as well as on octahedral sites in this system. This feature leads to large isotopic-effects between the two isotopes. The dependence of the thermodynamic functions like heat of solution, nonconfigurational entropy, specific heat and ordering temperatures from the composition of the isotope-mixture has been determined. (orig.)

  19. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  20. Isotope exchange reactions in hydrogen mixtures

    International Nuclear Information System (INIS)

    Czaplinski, W.; Gula, A.; Kravtsov, A.; Mikhailov, A.; Popov, N.

    1990-12-01

    The rates of isotopic exchange for the excited states of muonic hydrogen are calculated as functions of collision energy. Ground state population q 1s for different collision energies, target densities and isotope concentrations is obtained. It is shown that for principal quantum numbers n > 5 the isotopic exchange still considerably influences the value of q 1s . (author)

  1. Dynamical symmetry breaking in barium isotopes

    International Nuclear Information System (INIS)

    Rawat, Bir Singh; Chattopadhyay, P.K.

    1997-01-01

    The isotopes of Xe with mass numbers 124, 126, 128, 130 and the isotopes of barium with mass numbers 128, 130, 132, 134 were shown to correspond to the O(6) dynamical symmetry of IBM. In the investigation of the dynamical symmetry breaking in this region, the barium isotopes for departures from O(6) symmetry have been studied

  2. ICP-MS for isotope ratio measurement

    Science.gov (United States)

    The use of stable isotopes in mineral nutrition research has become a fundamental aspect of conducting this research. A gradual transition has occurred, now virtually complete, from radioactive isotope studies to those using stable isotopes. Although primarily used in human research, mineral stable ...

  3. Isotopes in day to day life

    Science.gov (United States)

    1984-06-01

    Developments are reported in the use of isotopic labeling and isotope irradiation in agriculture, medical science, hydrology, geochemistry, geophysics, environment pollution detection, and industries. Radioisotope instruments are described as well as techniques for gamma radiography, neutron radiography, and autoradiography. Isotope dating in geology and archaeology is covered. Basic scientific research topics in various areas are listed.

  4. Use of Isotopes for Studying Reaction Mechanisms

    Indian Academy of Sciences (India)

    In the first part of this series, we discussed how isotopes can be used as markers to determine the nature of intermediates in chemical reactions. The second part covered the effect of isotopes on equilibria and reactions, in processes where the bond to the isotopic a tom is broken. We showed with specific examples how.

  5. Radioactive isotopes on the Moon

    International Nuclear Information System (INIS)

    Davis, R. Jr.

    1975-01-01

    A limited review of experiments and studies of radioactivity and isotope ratios in lunar materials is given. Observations made on the first few millimeters of the surface where the effects of solar flare particles are important, some measurements on individual rocks, and some studies of radioactivities produced deep in the lunar soil by galactic cosmic rays, are among the experiments discussed

  6. Isotopes in the earth sciences

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, Robert

    1988-01-01

    This book examines significant aspects of isotope applications in geology and geochemistry commencing with basic matters, such as atomic structure, stable nuclides and their fractionation, as well as the various decay modes of unstable nuclides. Modern mass spectrometry techniques including electrostatic tandem accelerators are followed by a review of radioisotope dating technology. The relatively new method using the rare earth elements samarium and neodymium are covered. Other geochronometers, applicable to both rocks and minerals not dateable otherwise, are included. A review is given of isotopes in the atmosphere, hydrosphere and lithosphere of the Earth. Those of oxygen and hydrogen together with the cosmogenic radionuclides tritium and radiocarbon are discussed in relation to the biosphere. The role of isotopes of carbon, nitrogen and sulphur is described and extended to fossil fuels and rocks as well as meteorites. Related themes such as Phanerozoic oceans, oceanic palaeothermometry, snow and ice stratigraphy and geothermal waters are covered. The field of isotopic palaeoecology is discussed. Radioactive wastes, their accumulation, dangers and disposal are investigated with especial reference to their environmental impacts.

  7. Isotopes in the atomic age

    International Nuclear Information System (INIS)

    Arnikar, H.J.

    1989-01-01

    The first accessible, practical account of isotopes separation processes for engineers. This guide gives expert guidance on all the most important methods (including references to the original papers), how to improve their yields, with discussions of theory and application of each technique. Presentation is clear and non-mathematical. Illustrated

  8. Progress in tropical isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Schrag, D. P.; Poussart, P. F.; Anchukaitis, K. J.

    2005-12-01

    The terrestrial tropics remain an important gap in the growing high resolution proxy network used to characterize the mean state and variability of the hydrological cycle. Here we review early efforts to develop a new class of proxy paleorainfall/humidity indicators using intraseasonal to interannual-resolution stable isotope data from tropical trees. The approach invokes a recently published model of oxygen isotopic composition of alpha-cellulose, rapid methods for cellulose extraction from raw wood, and continuous flow isotope ratio mass spectrometry to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. Isotopically-derived age models may be confirmed for modern intervals using trees of known age, radiocarbon measurements, direct measurements of tree diameter, and time series replication. Studies are now underway at a number of laboratories on samples from Costa Rica, northwestern coastal Peru, Indonesia, Thailand, New Guinea, Paraguay, Brazil, India, and the South American Altiplano. Improved sample extraction chemistry and online pyrolysis techniques should increase sample throughput, precision, and time series replication. Statistical calibration together with simple forward modeling based on the well-observed modern period can provide for objective interpretation of the data. Ultimately, replicated data series with well-defined uncertainties can be entered into multiproxy efforts to define aspects of tropical hydrological variability associated with ENSO, the meridional overturning circulation, and the monsoon systems.

  9. Dual temperature isotope exchange system

    International Nuclear Information System (INIS)

    Spevack, J.S.

    1976-01-01

    Improvements in the method for isotope concentration by dual temperature exchange between feed and auxiliary fluids in a multistage system are described. In a preferred embodiment the first is a vaporizable liquid and the auxiliary fluid a gas, comprising steps for improving the heating and/or cooling and/or humidifying and/or dehumidifying operations

  10. Theory of oxygen isotope exchange

    NARCIS (Netherlands)

    den Otter, M.W.; Boukamp, Bernard A.; Bouwmeester, Henricus J.M.

    2001-01-01

    Transients for oxygen molecular mass numbers 32, 34 and 36 are derived which can be used for the interpretation of oxygen isotope exchange data based on measurement of concentrations of 16O2, 16O18O and 18O2 in the gas phase. Key parameters in the theory are the rate at which oxygen molecules are

  11. Reorientation measurements on tungsten isotopes

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, J J; Saladin, J X; Baktash, C; Alessi, J G [Pittsburgh Univ., Pa. (USA)

    1977-11-14

    In a particle-..gamma.. coincidence experiment, a thick tungsten target, of natural isotopic abundance, was bombarded with ..cap alpha.. and /sup 16/O beams. From analysis of the deexcitation ..gamma..-rays following Coulomb excitation, the spectroscopic quadrupole moment of the second 2/sup +/ state (the 2/sup +/' state) was determined for /sup 186/W and /sup 184/W. In a separate Coulomb excitation experiment a thin, isotopically enriched /sup 186/W target was bombarded with /sup 16/O ions. From analysis of projectiles scattered elastically and inelastically the quadrupole moment of the 2/sup +/' state of /sup 186/W was extracted. The results of the two experiments are in good agreement. The quadrupole moment of the 2/sup +/' state is found to be opposite in sign to that of the first 2/sup +/ state for both isotopes studied. However, its magnitude decreases rapidly in going from /sup 186/W to /sup 184/W, in contrast to the predictions of the rotation-vibration of asymmetric rotor models. The microscopic theory of Kumar and Baranger does predict the experimental trend, qualitatively. Thus the present results are interpreted as being evidence of strong coupling between ..beta.. and ..gamma.. degrees of freedom in the tungsten isotopes, which, according to the theory of Kumar and Baranger, is the source of the reduced value of the quadrupole moment.

  12. Triplet states in lead isotopes

    International Nuclear Information System (INIS)

    Naz, Tabassum; Ahmad, Shakeb; Abusara, H.

    2017-01-01

    Axial and triaxial calculations within RHB have been done to study the shape coexistence phenomena in the lead isotopes. Triplet states have been found in the 184-190 Pb which are in accordance with the experimental and other theoretical observations. The energy difference (in MeV) between the first two excited states also gives the evidence for the same

  13. Non-linear Isotope Effects

    DEFF Research Database (Denmark)

    Schmidt, Johan Albrecht

    ’s stratosphere is nearly mass dependent, and only a small fraction of the observed anomalous oxygen-17 excess can be attributed to N2O photolysis. In contrast, stratospheric photolysis produces a significant inverse clumped isotope effect.(ii) Stratospheric OCS photolysis significantly enrich the remaining OCS...

  14. The isotopic dating of crystals

    International Nuclear Information System (INIS)

    Giuliani, G.; Cheilletz, A.

    1995-01-01

    The first part of this work deals with the answer to the question : why are the crystals dated ? Then, some isotopic dating methods are described : U-Th-Pb, K-Ar, 40 Ar/ 39 Ar, Rb-Sr, Sm-Nd, fission traces, carbon 14 methods. Examples concerning emeralds and diamonds are given. (O.L.). 12 refs., 2 figs

  15. Isotope hydrology: Investigating groundwater contamination

    International Nuclear Information System (INIS)

    Dubinchuk, V.; Froehlich, K.; Gonfiantini, R.

    1989-01-01

    Groundwater quality has worsened in many regions, with sometimes serious consequences. Decontaminating groundwater is an extremely slow process, and sometimes impossible, because of the generally long residence time of the water in most geological formations. Major causes of contamination are poor groundwater management (often dictated by immediate social needs) and the lack of regulations and control over the use and disposal of contaminants. These types of problems have prompted an increasing demand for investigations directed at gaining insight into the behaviour of contaminants in the hydrological cycle. Major objectives are to prevent pollution and degradation of groundwater resources, or, if contamination already has occurred, to identify its origin so that remedies can be proposed. Environmental isotopes have proved to be a powerful tool for groundwater pollution studies. The IAEA has had a co-ordinated research programme since 1987 on the application of nuclear techniques to determine the transport of contaminants in groundwater. An isotope hydrology project is being launched within the framework of the IAEA's regional co-operative programme in Latin America (known as ARCAL). Main objectives are the application of environmental isotopes to problems of groundwater assessment and contamination in Latin America. In 1989, another co-ordinated research programme is planned under which isotopic and other tracers will be used for the validation of mathematical models in groundwater transport studies

  16. PETROCHEMISTRY, Pb ISOTOPE SYSTEMATICS, AND ...

    African Journals Online (AJOL)

    The petrology, geochemistry, geotectonic setting and common Pb isotope model ages for the granite gneisses in Ilesha schist belt have been studied and presented in this paper. These gneisses, apart from the normal rock-forming silicates, contain apatite, monazite, ilmenite and zircon in trace amounts. The occurrence of ...

  17. Plutonium determination by isotope dilution

    International Nuclear Information System (INIS)

    Lucas, M.

    1980-01-01

    The principle is to add to a known amount of the analysed solution a known amount of a spike solution consisting of plutonium 242. The isotopic composition of the resulting mixture is then determined by surface ionization mass spectrometry, and the plutonium concentration in the solution is deduced, from this measurement. For irradiated fuels neutronic studies or for fissile materials balance measurements, requiring the knowledge of the ratio U/Pu or of concentration both uranium and plutonium, it is better to use the double spike isotope dilution method, with a spike solution of known 233 U- 242 Pu ratio. Using this method, the ratio of uranium to plutonium concentration in the irradiated fuel solution can be determined without any accurate measurement of the mixed amounts of sample and spike solutions. For fissile material balance measurements, the uranium concentration is determined by using single isotope dilution, and the plutonium concentration is deduced from the ratio Pu/U and U concentration. The main advantages of isotope dilution are its selectivity, accuracy and very high sensitivity. The recent improvements made to surface ionization mass spectrometers have considerably increased the precision of the measurements; a relative precision of about 0.2% to 0.3% is obtained currently, but it could be reduced to 0.1%, in the future, with a careful control of the experimental procedures. The detection limite is around 0.1 ppb [fr

  18. Paleogene Seawater Osmium Isotope Records

    Science.gov (United States)

    Rolewicz, Z.; Thomas, D. J.; Marcantonio, F.

    2012-12-01

    Paleoceanographic reconstructions of the Late Cretaceous and early Cenozoic require enhanced geographic coverage, particularly in the Pacific, in order to better constrain meridional variations in environmental conditions. The challenge with the existing inventory of Pacific deep-sea cores is that they consist almost exclusively of pelagic clay with little existing age control. Pelagic clay sequences are useful for reconstructions of dust accumulation and water mass composition, but accurate correlation of these records to other sites requires improved age control. Recent work indicates that seawater Os isotope analyses provide useful age control for red clay sequences. The residence time of Os in seawater is relatively long compared to oceanic mixing, therefore the global seawater 187Os/188Os composition is practically homogeneous. A growing body of Late Cretaceous and Cenozoic data has constrained the evolution of the seawater Os isotopic composition and this curve is now a viable stratigraphic tool, employed in dating layers of Fe-Mn crusts (e.g., Klemm et al., 2005). Ravizza (2007) also demonstrated that the seawater Os isotopic composition can be extracted reliably from pelagic red clay sediments by analyzing the leached oxide minerals. The drawback to using seawater Os isotope stratigraphy to date Paleogene age sediments is that the compilation of existing data has some significant temporal gaps, notably between ~38 and 55 Ma. To improve the temporal resolution of the seawater Os isotope curve, we present new data from Ocean Drilling Program (ODP) Site 865 in the equatorial Pacific. Site 865 has excellent biostratigraphic age control over the interval ~38-55Ma. Preliminary data indicate an increase in the seawater composition from 0.427 at 53.4 Ma to 0.499 by 43 Ma, consistent with the apparent trend in the few existing data points. We also analyzed the Os isotopic composition recorded by oxide minerals at Integrated Ocean Drilling Program (IODP) Site U1370

  19. Can a sponge fractionate isotopes?

    Science.gov (United States)

    Patel, B; Patel, S; Balani, M C

    1985-03-22

    The study has unequivocally demonstrated that siliceous sponges Spirastrella cuspidifera and Prostylyssa foetida from the same microecological niche exhibit a high degree of species specificity, while accumulating a host of heavy metal ions (Ni, Cr, Cd, Sn, Ti, Mo, Zr). S. cuspidifera accumulated, in addition, 60Co and 63Ni, showing discrimination against other radionuclides, 137Cs and 131I, present in the ambient waters receiving controlled low level waste discharges from a B.W.R. nuclear power station. P. foetida, on the other hand, accumulated only 131I and showed discrimination against other radionuclides including 60Co, although the stable iodine concentrations in both the sponges were the same. The specific activity of 60Co (in becquerels per gram of 59Co) in S. cuspidifera and 131I (in becquerels per gram of 127I) in P. foetida were at least two orders of magnitude greater than in the ambient sea water. That of 63Ni (in becquerels per gram of 62Ni) in S. cuspidifera, on the other hand, was lower by two orders of magnitude than in either abiotic matrices from the same environment. Thus, not only did both the species show bioaccumulation of a specific element, but also preferential uptake of isotopes of the same element, though they were equally available for intake. Such differential uptake of isotopes can possibly be explained in terms of two quite different mechanisms operating, each applicable in a particular case. One is that the xenobiotic isotope enters the environment in a physicochemical form or as a complex different from that of its natural counterpart. If equilibration with the latter is slow, so that the organism acquires the xenobiotic in an unfamiliar chemical context, it may treat it as a chemically distinct entity so that its concentration factor differs from that of stable isotope, thus changing the specific activity. Alternatively, if the xenobiotic is present in the same chemical form as the stable isotope, the only way in which specific

  20. Deformation properties of lead isotopes

    International Nuclear Information System (INIS)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E.

    2016-01-01

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF 0 Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, 180 Pb and 184 Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF 0 functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF 0 functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron-rich lead isotopes undergo

  1. Isotope shifts in the late Permian of the Delaware Basin, Texas, precisely timed by varved sediments

    International Nuclear Information System (INIS)

    Magaritz, M.; Oregon Univ., Eugene; Anderson, R.Y.; Holser, W.T.; Saltzmann, E.S.; Garber, J.

    1983-01-01

    Closely spaced samples (285 in number) of varved sediments from the Upper Permian in Delaware Basin, Texas, have been analyzed for delta 13 Csub(carb), delta 13 Csub(org), delta 18 Osub(carb), Csub(org), Csub(carb) and calcite/dolomite. delta 13 C records a dramatic rise from -2.8 to + 5.7per mille in only 4400 years, detected in three sections across the basin, extrapolating smoothly through a 600-year interruption by a local (west side of the basin) fresh-water inflow evidenced by low delta 18 O. This continuity and low Csub(org) within the basin, both indicate that the excess net deposition of Csub(org), necessary to generate the rise in delta 13 C, took place in the ocean external to the Delaware Basin, Correlation with similar records from the Zechstein Basin suggest that the event was world-wide, although this poses obvious difficulties for the carbon cycle. The rate of rise of delta 13 C, and its sustained high level, must imply conversions of oxidized carbon to reduced carbon that are very large depending on which reservoirs were involved. (orig.)

  2. The isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, Ch [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  3. The isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, Ch. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In the early years of isotope separation, and in particular electromagnetic isotope separation, needs for rapid results have conducted to empiric research. This paper describes fundamental research on the electromagnetic isotope separation to a better understanding of isotope separators as well as improving the performances. Focus has been made on the study of the principle of isotope contamination and the remedial action on the separator to improve the isotope separation ratio. In a first part, the author come back to the functioning of an electromagnetic separator and generalities on isotope contamination. Secondly, it describes the two stages separation method with two dispersive apparatus, an electromagnetic separation stage followed by an electrostatic separation stage, both separated by a diaphragm. The specifications of the electrostatic stage are given and its different settings and their consequences on isotope separation are investigated. In a third part, mechanisms and contamination factors in the isotope separation are discussed: natural isotope contamination, contamination by rebounding on the collector, contamination because of a low resolution, contamination by chromatism and diffusion effect, breakdown of condenser voltage. Analysis of experimental results shows the diffusion as the most important contamination factor in electromagnetic isotope separation. As contamination factors are dependent on geometric parameters, sector angle, radius of curvature in the magnetic field and clearance height are discussed in a fourth part. The better understanding of the mechanism of the different contamination factors and the study of influential parameters as pressure and geometric parameters lead to define a global scheme of isotope contamination and determinate optima separator design and experimental parameters. Finally, the global scheme of isotope contamination and hypothesis on optima specifications and experimental parameters has been checked during a

  4. Method for separating gaseous mixtures of isotopes

    International Nuclear Information System (INIS)

    Neimann, H.J.; Schuster, E.; Kersting, A.

    1976-01-01

    A gaseous mixture of isotopes is separated by laser excitation of the isotope mixture with a narrow band of wavelengths, molecularly exciting mainly the isotope to be separated and thereby promoting its reaction with its chemical partner which is excited in a separate chamber. The excited isotopes and the chemical partner are mixed, perhaps in a reaction chamber to which the two excited components are conducted by very short conduits. The improvement of this method is the physical separation of the isotope mixture and its partner during excitation. The reaction between HCl and the mixture of 238 UF 6 and 235 UF 6 is discussed

  5. Isotopic anomalies - chemical memory of Galactic evolution

    International Nuclear Information System (INIS)

    Clayton, D.D.

    1988-01-01

    New mechanisms for the chemical memory of isotopic anomalies are proposed which are based on the temporal change during the chemical evolution of the Galaxy of the isotopic composition of the mean ejecta from stars. Because of the differing temporal evolution of primary and secondary products of nucleosynthesis, the isotopic composition of the bulk interstellar medium changes approximately linearly with time, and thus any dust component having an age different from that of average dust will be isotopically anomalous. Special attention is given to C, O, Mg, Si, and isotopically heavy average-stellar condensates of SiC. 20 references

  6. Uranium isotope separation using styrene cation exchangers

    International Nuclear Information System (INIS)

    Kahovec, J.

    1980-01-01

    The separation of 235 U and 238 U isotopes is carried out either by simple isotope exchange in the system uranium-cation exchanger (sulphonated styrene divinylbenzene resin), or by combination of isotope exchange in a uranium-cation exchanger (Dowex 50, Amberlite IR-120) system and a chemical reaction. A review is presented of elution agents used, the degree of cation exchanger cross-linking, columns length, and 235 U enrichment. The results are described of the isotope effect study in a U(IV)-U(VI)-cation exchanger system conducted by Japanese and Romanian authors (isotope exchange kinetics, frontal analysis, reverse (indirect) frontal analysis). (H.S.)

  7. Isotopic composition of cosmic ray nuclei

    International Nuclear Information System (INIS)

    Enge, W.

    1976-01-01

    A review will be given on the role of cosmic ray isotopes as tracers of the astrophysical nucleo-synthesis. The products of every nuclear burning chain are first of all isotopes and not elements. Thus, it is the study of the isotopes rather than that of the elements that responds to the questions on these nucleo-synthetic reactions. The problems concerning the solar system isotopic abundances and the cosmic ray isotopic abundances as well as a comparison between both will be presented. Furthermore the present stage of the experimental techniques and the latest results will be discussed. (orig.) [de

  8. 2. Workshop 'Isotopes in Nature'. 1

    International Nuclear Information System (INIS)

    1979-11-01

    The workshop was aimed at discussing in detail the following problems: (1) distribution of stable and radioactive isotopes in nature, (2) theoretical and experimental studies of isotopic effects in natural processes, (3) problems of sample preparation and sample measurement in determining the relative abundance of stable isotopes or radioactive isotopes in nature, (4) age estimations of samples from different areas of the geosphere, (5) contributions to the specification of global and regional substance cycles in nature with the aid of isotopic and geochemical studies. 75 summaries are included

  9. The centenary of the discovery of isotopes

    International Nuclear Information System (INIS)

    Soulie, Edgar

    2013-01-01

    This article recalls works performed by different scientists (Marckwald and Keetman, Stromholm and Svedberg, Soddy, Thompson, Aston) which resulted in the observation and identification of the existence of isotopes. The author also recalls various works related to mechanisms of production of isotopes, the discovery of uranium fission and the principle of chain reaction. The author notably evokes French scientists involved in the development of mass spectroscopy and in the research and applications on isotopes within the CEA after the Second World War. A bibliography of article and books published by one of them, Etienne Roth, is provided. References deal with nuclear applications of chemical engineering (heavy water and its production, chemical processes in fission reactors, tritium extraction and enrichment), isotopic fractioning and physical-chemical processes, mass spectrometry and isotopic analysis, isotopic geochemistry (on 07;Earth, search for deuterium in moon rocks and their consequences), first dating and the Oklo phenomenon, radioactive dating, water and climate (isotopic hydrology, isotopes and hailstone formation, the atmosphere), and miscellaneous scientific fields (nuclear measurements and radioactivity, isotopic abundances and atomic weight, isotopic separation and use of steady isotopes)

  10. Mass fractionation processes of transition metal isotopes

    Science.gov (United States)

    Zhu, X. K.; Guo, Y.; Williams, R. J. P.; O'Nions, R. K.; Matthews, A.; Belshaw, N. S.; Canters, G. W.; de Waal, E. C.; Weser, U.; Burgess, B. K.; Salvato, B.

    2002-06-01

    Recent advances in mass spectrometry make it possible to utilise isotope variations of transition metals to address some important issues in solar system and biological sciences. Realisation of the potential offered by these new isotope systems however requires an adequate understanding of the factors controlling their isotope fractionation. Here we show the results of a broadly based study on copper and iron isotope fractionation during various inorganic and biological processes. These results demonstrate that: (1) naturally occurring inorganic processes can fractionate Fe isotope to a detectable level even at temperature ˜1000°C, which challenges the previous view that Fe isotope variations in natural system are unique biosignatures; (2) multiple-step equilibrium processes at low temperatures may cause large mass fractionation of transition metal isotopes even when the fractionation per single step is small; (3) oxidation-reduction is an importation controlling factor of isotope fractionation of transition metal elements with multiple valences, which opens a wide range of applications of these new isotope systems, ranging from metal-silicate fractionation in the solar system to uptake pathways of these elements in biological systems; (4) organisms incorporate lighter isotopes of transition metals preferentially, and transition metal isotope fractionation occurs stepwise along their pathways within biological systems during their uptake.

  11. Isotope hydrology of catchment basins: lithogenic and cosmogenic isotopic systems

    Energy Technology Data Exchange (ETDEWEB)

    Nimz, G. J., LLNL

    1998-06-01

    A variety of physical processes affect solute concentrations within catchment waters. The isotopic compositions of the solutes can indicate which processes have determined the observed concentrations. These processes together constitute the physical history of the water. Many solutes in natural waters are derived from the interaction between the water and the rock and/or soil within the system - these are termed `lithogenic` solutes. The isotopic compositions of these solutes provide information regarding rock-water interactions. Many other solutes have their isotopic compositions determined both within and outside of the catchment - i.e., in addition to being derived from catchment rock and soil, they are solutes that are also transported into the catchment. Important members of this group include solutes that have isotopic compositions produced by atomic particle interactions with other nuclides. The source of the atomic particles can be cosmic radiation (producing `cosmogenic` nuclides in the atmosphere and land surface), anthropogenic nuclear reactions (producing `thermonuclear` nuclides), or radioactive and fission decay of naturally-occurring elements, principally {sup 238}U (producing `in-situ` lithogenic nuclides in the deep subsurface). Current language usage often combines all of the atomic particle-produced nuclides under the heading `cosmogenic nuclides`, and for simplicity we will often follow that usage here, although always indicating which variety is being discussed. This paper addresses the processes that affect the lithogenic and cosmogenic solute concentrations in catchment waters, and how the isotopic compositions of the solutes can be used in integrative ways to identify these processes, thereby revealing the physical history of the water within a catchment system. The concept of a `system` is important in catchment hydrology. A catchment is the smallest landscape unit that can both participate in all of the aspects of the hydrologic cycle and

  12. Isotopic contamination in electromagnetic isotope separators; La contagion isotopique dans les separateurs electromagnetiques d'isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Cassignol, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The mechanisms producing isotopic contamination in the electromagnetic separation of isotopes are studied with the aid of the Separator of Saclay and an electrostatic analyzer in cascade. After a separate investigation the result of which is that no contamination comes from the spreading of initial energies of ions, two principal mechanisms are emphasized; scattering and instability of the regime of the sources. The characters of each type of contamination arising from both mechanisms are described in some detail. An unique scheme of isotopic contamination is then derived from the partial ones. This scheme is successfully verified in several experimental separations. The applications concern principally the performances of magnetic cascades and more complex apparatus. It is found that the isotopic purities that such machines can deliver are extremely high. (author) [French] On a etudie, a l'aide du separateur de Saclay et d'un analyseur electrostatique en cascade, les mecanismes par lesquels est produite la contamination isotopique dans la separation electromagnetique des isotopes. A la suite d'une deuxieme etude, qui a mene a la conclusion que la contamination ne provient pas d'une dispersion des energies initiales des ions, on propose deux mecanismes comme etant les plus importants; la diffusion et l'instabilite du regime des sources. On decrit en quelques details la nature de la contamination provenant de deux types de mecanisme. On deduit de ces deux mecanismes un seul schema qui a ete ensuite verifie par plusieurs separations experimentales. Les applications interessent surtout les performances des cascades magnetiques et les appareillages plus complexes. On trouve que les puretes isotopiques que peuvent fournir de tels appareils sont tres elevees. (auteur)

  13. Methane clumped isotopes: Progress and potential for a new isotopic tracer

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, Peter M. J.; Stolper, Daniel A.; Eiler, John M.; Sessions, Alex L.; Lawson, Michael; Shuai, Yanhua; Bishop, Andrew; Podlaha, Olaf G.; Ferreira, Alexandre A.; Santos Neto, Eugenio V.; Niemann, Martin; Steen, Arne S.; Huang, Ling; Chimiak, Laura; Valentine, David L.; Fiebig, Jens; Luhmann, Andrew J.; Seyfried, William E.; Etiope, Giuseppe; Schoell, Martin; Inskeep, William P.; Moran, James J.; Kitchen, Nami

    2017-11-01

    The isotopic composition of methane is of longstanding geochemical interest, with important implications for understanding hydrocarbon systems, atmospheric greenhouse gas concentrations, the global carbon cycle, and life in extreme environments. Recent analytical developments focusing on multiply substituted isotopologues (‘clumped isotopes’) are opening a potentially valuable new window into methane geochemistry. When methane forms in internal isotopic equilibrium, clumped isotopes can provide a direct record of formation temperature, making this property particularly valuable for identifying different methane origins. However, it has also become clear that in certain settings methane clumped isotope measurements record kinetic rather than equilibrium isotope effects. Here we present a substantially expanded dataset of methane clumped isotope analyses, and provide a synthesis of the current interpretive framework for this parameter. We review different processes affecting methane clumped isotope compositions, describe the relationships between conventional isotope and clumped isotope data, and summarize the types of information that this measurement can provide in different Earth and planetary environments.

  14. A Black Hills-Madison Aquifer origin for Dakota Aquifer groundwater in northeastern Nebraska.

    Science.gov (United States)

    Stotler, Randy; Harvey, F Edwin; Gosselin, David C

    2010-01-01

    Previous studies of the Dakota Aquifer in South Dakota attributed elevated groundwater sulfate concentrations to Madison Aquifer recharge in the Black Hills with subsequent chemical evolution prior to upward migration into the Dakota Aquifer. This study examines the plausibility of a Madison Aquifer origin for groundwater in northeastern Nebraska. Dakota Aquifer water samples were collected for major ion chemistry and isotopic analysis ((18)O, (2)H, (3)H, (14)C, (13)C, (34)S, (18)O-SO(4), (87)Sr, (37)Cl). Results show that groundwater beneath the eastern, unconfined portion of the study area is distinctly different from groundwater sampled beneath the western, confined portion. In the east, groundwater is calcium-bicarbonate type, with delta(18)O values (-9.6 per thousand to -12.4 per thousand) similar to local, modern precipitation (-7.4 per thousand to -10 per thousand), and tritium values reflecting modern recharge. In the west, groundwater is calcium-sulfate type, having depleted delta(18)O values (-16 per thousand to -18 per thousand) relative to local, modern precipitation, and (14)C ages 32,000 to more than 47,000 years before present. Sulfate, delta(18)O, delta(2)H, delta(34)S, and delta(18)O-SO(4) concentrations are similar to those found in Madison Aquifer groundwater in South Dakota. Thus, it is proposed that Madison Aquifer source water is also present within the Dakota Aquifer beneath northeastern Nebraska. A simple Darcy equation estimate of groundwater velocities and travel times using reported physical parameters from the Madison and Dakota Aquifers suggests such a migration is plausible. However, discrepancies between (14)C and Darcy age estimates indicate that (14)C ages may not accurately reflect aquifer residence time, due to mixtures of varying aged water.

  15. Tequila authenticity assessment by headspace SPME-HRGC-IRMS analysis of 13C/12C and 18O/16O ratios of ethanol.

    Science.gov (United States)

    Aguilar-Cisneros, Blanca O; López, Mercedes G; Richling, Elke; Heckel, Frank; Schreier, Peter

    2002-12-18

    By use of headspace SPME sampling and a PLOT column, on-line capillary gas chromatography-isotope ratio mass spectrometry was employed in the combustion (C) and the pyrolysis (P) modes (HRGC-C/P-IRMS) to determine the delta(13)C(VPDB) and delta(18)O(VSMOW) values of ethanol in authentic (n = 14) and commercial tequila samples (n = 15) as well as a number of other spirits (n = 23). Whereas with delta(13)C(VPDB) values ranging from -12.1 to -13.2 per thousand and from -12.5 to -14.8 per thousand similar variations were found for 100% agave and mixed tequilas, respectively, the delta(18)O(VSMOW) data differed slightly within these categories: ranges from +22.1 to +22.8 per thousand and +20.8 to +21.7 per thousand were determined for both the authentic 100% agave and mixed products, respectively. The data recorded for commercial tequilas were less homogeneous; delta(13)C(VPDB) data from -10.6 to -13.9 per thousand and delta(18)O(VSMOW) values from +15.5 to +22.7 per thousand were determined in tequilas of both categories. Owing to overlapping data, attempts to differentiate between white, rested, and aged tequilas within each of the two categories failed. In addition, discrimination of tequila samples from other spirits by means of delta(13)C(VPDB) and delta(18)O(VSMOW) data of ethanol was restricted to the products originating from C(3) as well as C(4)/CAM raw materials.

  16. Natural fractionation of uranium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Noordmann, Janine

    2015-01-24

    The topic of this thesis was the investigation of U (n({sup 238}U) / n({sup 235}U)) isotope variations in nature with a focus on samples (1) that represent the continental crust and its weathering products (i.e. granites, shales and river water) (2) that represent products of hydrothermal alteration on mid-ocean ridges (i.e. altered basalts, carbonate veins and hydrothermal water) and (3) from restricted euxinic basins (i.e. from the water column and respective sediments). The overall goal was to explore the environmental conditions and unravel the mechanisms that fractionate the two most abundant U isotopes, n({sup 238}U) and n({sup 235}U), on Earth.

  17. Commercialization of DOE isotope production

    International Nuclear Information System (INIS)

    Laflin, S.

    1997-01-01

    This paper describes the business structure and operations of MAC Isotopes (MACI) L.L.C., a newly created business resulting from the commercialization of a former U.S. Department of Energy (DOE) mission at the Idaho National Engineering and Environmental Laboratory (INEEL). MACI began its commercial operations on October 1, 1996, and is the first U.S. commercial isotope production business to result from the commercialization of DOE facilities or programs. The commercialization was the culmination of an -2-yr competitive procurement process by the DOE and Lockheed Martin Idaho Technologies Company (LMITCO). MACI was selected from this competitive process as the commercial business of choice on the basis of providing the best value to the DOE/LMITCO and having the greatest potential for commercial success

  18. Nuclides and isotopes. Twelfth edition

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This explanatory booklet was designed to be used with the Chart of the Nuclides. It contains a brief history of the atomic theory of matter: ancient speculations, periodic properties of elements (Mendeleev table), radioactivity, early models of atomic structure, the Bohr atom, quantum numbers, nature of isotopes, artificial radioactivity, and neutron fission. Information on the pre-Fermi (natural) nuclear reactor at Oklo and the search for superheavy elements is given. The booklet also discusses information presented on the Chart and its coding: stable nuclides, metastable states, data display and color, isotopic abundances, neutron cross sections, spins and parities, fission yields, half-life variability, radioisotope power and production data, radioactive decay chains, and elements without names. The Periodic Table of the Elements is appended. 3 figures, 3 tables

  19. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    1991-01-01

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Reports in this issue give U-Pb zircon ages for rocks in Newfoundland, Yukon Territory, Manitoba, Ontario, and the Northwest Territories; present a compilation of K-Ar ages; and discuss Precambrian activity in New Brunswick, the geochronology of rock from the Northwest Territories, and reconnaissance Nd studies of rocks from the Northwest Territories. (figs., tabs., refs.)

  20. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    1992-01-01

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Report 5 contains 24 papers from most regions of Canada, but particularly from British Columbia. The Geochronology Laboratory has, over the years, provided substantial U-Pb dating for the Cordilleran Division of the Geological Survey of Canada in Vancouver, and the results of a number of these studies are presented this year. A compilation of K-Ar ages is given. (figs., tabs., refs.)

  1. Isotope hydrology in Latin America

    Energy Technology Data Exchange (ETDEWEB)

    Payne, B R [International Atomic Energy Agency, Division of Research and Laboratories, Isotope Hydrology Section, Vienna (Austria)

    1972-07-01

    A wide variety of problems in hydrology have proved susceptible to the use of nuclear techniques. Conclusions may be drawn from the relative abundances of certain 'environmental isotopes', such as heavy stable isotopes of hydrogen and oxygen in water molecules, tritium, carbon-14 and silicon-32, in atmospheric, surface or ground water; origin and rate of flow, for example, may be deduced. Artificial radioisotopes may be used similarly as a logical extension to well-known tracer techniques using dyes and salts. Inherent in the use of such radiotracers are the advantages of very high detection sensitivity (and thus very low required concentrations and the elimination of density effects), and a choice of a variety of nuclides alien to the geohydrological system (and hence unique identification and low background). (author)

  2. Strange Isotope Ratios in Jupiter

    Science.gov (United States)

    Manuel, O.; Ragland, D.; Windler, K.; Zirbel, J.; Johannes, L.; Nolte, A.

    1998-05-01

    At the January AAS meeting, Dr. Daniel Goldin ordered the release of isotopic data from the 1995 Galileo probe into Jupiter. This probe took mass readings for mass numbers 2-150, which includes all of the noble gas isotopes. A certain few noble gas isotopes, specifically those at mass/charge = 21, 40, 78, 124, and 126, are difficult to distinguish from background, while interference causes some variation in signals for noble gas isotopes at mass/charge = 20, 22, 36, 38, 40, 80, 82, 83, 84 and 86. Some contamination was caused by incomplete adsorption of low mass hydrocarbons by Carbosieve, the material used in the concentration cells [Space Sci. Rev. 60, 120 (1992)]. Thus, preliminary results are most reliable in the high mass region that includes xenon. The Galileo Probe provided the first direct measurements from a planet with a chemical composition drastically different from Earth. Our preliminary analyses indicate that Jupiter contains Xe-X [Nature 240, 99 (1972)], which differs significantly from Earth's xenon. Xe-X and primordial He are tightly coupled on the microscopic scale of meteorite minerals [Science 195, 208 (1977); Meteoritics 15, 117 (1980)]. The presence today of Xe-X in the He-rich atmosphere of Jupiter suggests that the primordial linkage of Xe-X with He extended across the protosolar nebula, on a planetary scale [Comments Astrophys. 18, 335 (1997)]. Contamination by hydrocarbons and other gases does not necessarily remove light noble gases from further consideration. Currently, isolation of signals of these elements from interference continues and may result in the presentation of many other interesting observations at the conference.

  3. Titanium isotopic anomalies in meteorites

    International Nuclear Information System (INIS)

    Niemeyer, S.; Lugmair, G.W.

    1984-01-01

    High-precision analyses of Ti are reported for samples from a variety of meteorite classes. The expanded data base for Allende inclusions still shows Ti isotope anomalies in every inclusion. All the coarse-grained inclusions give quite similar patterns, but fine-grained inclusions show more variable, and sometimes larger, anomalies. One inclusion, 3675A, was analyzed because others identified it as a possible 'FUN' inclusion due to its mass-fractionated Mg. This designation is supported by the significantly more complex Ti isotopic pattern for 3675A compared to all our other Allende inclusions. Available data fail to suggest that any particular Allende mineral phase, including a chromite-carbon fraction from an acid residue, is especially rich in anomalous Ti. We also find anomalous Ti in a bulk sample of a C1 chondrite and in matrix separates from C2 chondrites. The excesses of 50 Ti are smaller than for Allende inclusions, and subtle differences in Ti isotopic patterns tentatively suggest that parent materials for C1-C2 matrix and Allende inclusions are not directly related. Analyses of chondrules from unequilibrated ordinary chondrites did not yield clear evidence for anomalous Ti, but some 'larger than usual' deficits at 50/46 give encouragement for future work in this direction. (author)

  4. Isotope exchange process and device

    International Nuclear Information System (INIS)

    Delvalle, Pierre.

    1974-01-01

    A process for enriching uranium in one of its isotopes is described. To do so, cascade isotopic exchanges are made by contact between U(III) and U(IV) in conditions avoiding the oxidation of U(III) in U(IV). A liquid phase containing an uranium compound and free of other group III to VIII metals of the periodic classification, in which uranium is present at a first valence is placed in contact with a second valence uranium compound, protected from any contact with a conducting solid and with an agent bringing free or release oxygen. The second phase is organic. The process includes a counter current isotopic exchange between an aqueous phase containing a U +4 salting-out agent and the uranium as U +3 ions and an organic phase containing the uranium at valence IV. This is followed by the extraction of U(IV) from the organic phase into the previously spent aqueous phase and the reduction of uranium from valence IV to valence III; finally by oxidation of U(III) of the aqueous phase into U(IV) and the transfer of U(IV) into the previously exhausted organic phase [fr

  5. Radiogenic age and isotopic studies

    International Nuclear Information System (INIS)

    Parrish, R.R.

    1990-01-01

    This is one of an annual collection of reports presenting data from the Geochronology Section of the Continental Geoscience Division of the Geological Survey of Canada (GSC). The main purpose of this collection is to make geochronological and other radiogenic isotope data produced by the section available promptly to the geological community. Reports make full presentation of the data, relate these to field settings and make comparatively short interpretations. Other geochronological and isotope data produced in the laboratory but published in outside journals or separate GSC publications are summarized at the end of this report. Reports in this issue cover methods for Rb-Sr and Sm-Nd isotopic analyses; 40 Ar- 39 Ar ages for the New Quebec Crater and for basaltic rocks; U-Pb ages for a differentiated mafic sill in the Ogilvie Mountains, plutonic rocks in the Contwoyto-Nose Lakes are, zircons from the Anton Complex, the Clinton-Colden gabbro-anorthosite intrusion, the Himag plutonic suite, the Campbell granite, the Central Gneiss Belt, Silurian granites, a metarhyolite, plagiogranite and gabbro, and the Wage shear zone; Rb-Sr ages for granitic rocks; K-Ar and Rb-Sr geochronology of granites; a compilation of K-Ar ages; ages of archean and proterozoic mylonites and pre-Misi granitoid domes; and reconnaissance geochronology of Baffin Island

  6. Neodymium isotopic variations in seawater

    International Nuclear Information System (INIS)

    Piepgras, D.J.; Wasserburg, G.J.

    1980-01-01

    New data for the direct measurement of the isotopic composition of neodymium in Atlantic Ocean seawater are compared with previous measurements of Pacific Ocean seawater and ferromanganese sediments from major ocean basins. Data for Atlantic seawater are in excellent agreement with Nd isotopic measurements made on Atlantic ferromanganese sediments and are distinctly different from the observed compositions of Pacific samples. These results clearly demonstrate the existence of distinctive differences in the isotopic composition of Nd in the waters of the major ocean basins and are characteristic of the ocean basin sampled. The average epsilonsub(N)sub(d)(0) values for the major oceans as determined by data from seawater and ferromanganese sediments are as follows: Atlantic Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 12 +- 2; Indian Ocean, epsilonsub(N)sub(d)(0) approx. equal to - 8 +- 2; Pacific Ocean, epsilonsub(N)sub(d)(0) approx. equal to -3 +- 2. These values are considerably less than epsilonsub(N)sub(d)(0) value sources with oceanic mantle affinities indicating that the REE in the oceans are dominated by continental sources. The difference in the absolute abundance of 143 Nd between the Pacific and Atlantic Oceans corresponds to approx. 10 6 atoms 143 Nd per gram of seawater. The correspondence between the 143 Nd/ 144 Nd in seawater and in the associated sediments suggests the possible application of this approach to paleo-oceanography. (orig./HAE)

  7. A novel methodology to investigate isotopic biosignatures

    Science.gov (United States)

    Horner, T. J.; Lee, R. B. Y.; Henderson, G. M.; Rickaby, R. E. M.

    2012-04-01

    An enduring goal of trace metal isotopic studies of Earth History is to find isotopic 'fingerprints' of life or of life's individual physiochemical processes. Generally, such signatures are sought by relating an isotopic effect observed in controlled laboratory conditions or a well-characterized environment to a more complex system or the geological record. However, such an approach is ultimately limited because life exerts numerous isotopic fractionations on any one element so it is hard to dissect the resultant net fractionation into its individual components. Further, different organisms, often with the same apparent cellular function, can express different isotopic fractionation factors. We have used a novel method to investigate the isotopic fractionation associated with a single physiological process-enzyme specific isotopic fractionation. We selected Cd isotopes since only one biological use of Cd is known, CdCA (a Cd/Zn carbonic anhydrase from the coastal diatom T. Weissflogii). Thus, our investigation can also inform the long standing mystery as to why this generally toxic element appears to have a nutrient-like dissolved isotopic and concentration profile in the oceans. We used the pET-15b plasmid to insert the CdCA gene into the E. coli genome. There is no known biochemical function for Cd in E. coli, making it an ideal vector for studying distinct physiological processes within a single organism. The uptake of Cd and associated isotopic fractionation was determined for both normal cells and those expressing CdCA. It was found that whole cells always exhibited a preference for the light isotopes of Cd, regardless of the expression of CdCA; adsorption of Cd to cell surfaces was not seen to cause isotopic fractionation. However, the cleaning procedure employed exerted a strong control on the observed isotopic composition of cells. Using existing protein purification techniques, we measured the Cd isotopic composition of different subcellular fractions of E

  8. Deformation properties of lead isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Tolokonnikov, S. V.; Borzov, I. N.; Lutostansky, Yu. S.; Saperstein, E. E., E-mail: saper43-7@mail.ru [National Research Center Kurchatov Institute (Russian Federation)

    2016-01-15

    The deformation properties of a long lead isotopic chain up to the neutron drip line are analyzed on the basis of the energy density functional (EDF) in the FaNDF{sup 0} Fayans form. The question of whether the ground state of neutron-deficient lead isotopes can have a stable deformation is studied in detail. The prediction of this deformation is contained in the results obtained on the basis of the HFB-17 and HFB-27 Skyrme EDF versions and reported on Internet. The present analysis reveals that this is at odds with experimental data on charge radii and magnetic moments of odd lead isotopes. The Fayans EDF version predicts a spherical ground state for all light lead isotopes, but some of them (for example, {sup 180}Pb and {sup 184}Pb) prove to be very soft—that is, close to the point of a phase transition to a deformed state. Also, the results obtained in our present study are compared with the predictions of some other Skyrme EDF versions, including SKM*, SLy4, SLy6, and UNE1. By and large, their predictions are closer to the results arising upon the application of the Fayans functional. For example, the SLy4 functional predicts, in just the same way as the FaNDF{sup 0} functional, a spherical shape for all nuclei of this region. The remaining three Skyrme EDF versions lead to a deformation of some light lead isotopes, but their number is substantially smaller than that in the case of the HFB-17 and HFB-27 functionals. Moreover, the respective deformation energy is substantially lower, which gives grounds to hope for the restoration of a spherical shape upon going beyond the mean-field approximation, which we use here. Also, the deformation properties of neutron-rich lead isotopes are studied up to the neutron drip line. Here, the results obtained with the FaNDF{sup 0} functional are compared with the predictions of the HFB-17, HFB-27, SKM*, and SLy4 Skyrme EDF versions. All of the EDF versions considered here predict the existence of a region where neutron

  9. Isotope analysis of closely adjacent minerals

    International Nuclear Information System (INIS)

    Smith, M.P.

    1990-01-01

    This patent describes a method of determining an indicator of at least one of hydrocarbon formation, migration, and accumulation during mineral development. It comprises: searching for a class of minerals in a mineral specimen comprising more than one class of minerals; identifying in the mineral specimen a target sample of the thus searched for class; directing thermally pyrolyzing laser beam radiation onto surface mineral substance of the target sample in the mineral specimen releasing surface mineral substance pyrolysate gases therefrom; and determining isotope composition essentially of the surface mineral substance from analyzing the pyrolysate gases released from the thus pyrolyzed target sample, the isotope composition including isotope(s) selected from the group consisting of carbon, hydrogen, and oxygen isotopes; determining an indicator of at least one of hydrocarbon formation, migration, and accumulation during mineral development of the target mineral from thus determined isotope composition of surface mineral substance pyrolysate

  10. Isotope exchange in oxide-containing catalyst

    Science.gov (United States)

    Brown, Kenneth G. (Inventor); Upchurch, Billy T. (Inventor); Hess, Robert V. (Inventor); Miller, Irvin M. (Inventor); Schryer, David R. (Inventor); Sidney, Barry D. (Inventor); Wood, George M. (Inventor); Hoyt, Ronald F. (Inventor)

    1989-01-01

    A method of exchanging rare-isotope oxygen for common-isotope oxygen in the top several layers of an oxide-containing catalyst is disclosed. A sample of an oxide-containing catalyst is exposed to a flowing stream of reducing gas in an inert carrier gas at a temperature suitable for the removal of the reactive common-isotope oxygen atoms from the surface layer or layers of the catalyst without damaging the catalyst structure. The reduction temperature must be higher than any at which the catalyst will subsequently operate. Sufficient reducing gas is used to allow removal of all the reactive common-isotope oxygen atoms in the top several layers of the catalyst. The catalyst is then reoxidized with the desired rare-isotope oxygen in sufficient quantity to replace all of the common-isotope oxygen that was removed.

  11. Stable Oxygen-18 and Deuterium Isotopes

    DEFF Research Database (Denmark)

    Müller, Sascha

    The application of stable Oxygen-18 (18O) and Deuterium (2H) isotopes, as a tracer for fluxes between different compartments of the water cycle was subject of the present PhD-thesis. During a three year period, temporal data from a wide range of water cycle constituents was collected from...... the Skjern River catchment, Denmark. The presented applications focused on studying the isotopic 'input signal' to the hydrosphere in the form of precipitation, the isotopic 'output signal' with its related dynamic processes at a coastal saltwater-freshwater interface (groundwater isotopes) and the temporal...... development within a given lowland headwater catchment (stream water isotopes). Based on our investigations on the precipitation isotopic composition a local meteoric water line (LMWL) was constructed and expressed as: δ2H=7.4 δ18O + 5.36‰. Moreover, we showed that under maritime temperature climate influence...

  12. Sulphur isotope variations in the atmosphere

    International Nuclear Information System (INIS)

    Newman, L.; Krouse, H.R.; Grinenko, V.A.

    1991-01-01

    The measurement of the isotope ratios of sulphur and oxygen can in principal be used to assess sulphur inputs into, transformation within, and removal from the atmosphere. Major inputs arise from both anthropogenic and biogenic activities. Transformations arise from oxidation, neutralization, and other chemical reactions. Advection causes dilution and the main removal processes are dry deposition (governed by gravitation and diffusion) and rain. The admixture of sources can be discerned from their isotopic signatures whereas transformations and removal can be followed from the isotopic fractionation that might occur. In this chapter, the atmospheric sulphur cycle and the associated chemistry are summarized. Also presented is information on natural isotopic variations and fundamental concepts relating to the use of isotopic data to delineate anthropogenic S in the atmosphere. Examples of successful applications of these concepts are given. Finally, consideration is given to the potential of using isotopically enriched sulphur to study transport and transformation of atmospheric S compounds. Refs, figs and tabs

  13. Laser photochemical separation of hydrogen isotopes

    International Nuclear Information System (INIS)

    Fowler, M.C.

    1979-01-01

    A method of separating isotopes of hydrogen utilizing isotopically selective photodissociation of organic acid is disclosed. Specifically acetic or formic acid containing compounds of deuterated nd hydrogenated acid is irradiated by radiation having a wavelength in the infrared spectrum between 9.2 to 10.8 microns to produce deuterium hydroxide and deuterium hydride respectively. Maintaining the acid at an elevated temperature significantly improves the yield of isotope separation

  14. Atomic masses of rare-earth isotopes

    International Nuclear Information System (INIS)

    Schmidt-Ott, W.D.; Kantus, R.; Runte, E.

    1981-01-01

    A survey is given of decay energies of rare-earth isotopes measured in electron-capture decay by relative Psub(K) ratios, ECsub(K)/β + , and EC/β + ratios. Atomic masses of A = 147 isotopes and of 146 Gd and 148 Dy were derived. The masses of these isotopes and of α-decaying precessors are compared with predictions of current mass formulae. The subshell closure at Z = 64 is shown for N = 82, and 84 isotones. (orig.)

  15. Normalization of oxygen and hydrogen isotope data

    Science.gov (United States)

    Coplen, T.B.

    1988-01-01

    To resolve confusion due to expression of isotopic data from different laboratories on non-corresponding scales, oxygen isotope analyses of all substances can be expressed relative to VSMOW or VPDB (Vienna Peedee belemnite) on scales normalized such that the ??18O of SLAP is -55.5% relative to VSMOW. H3+ contribution in hydrogen isotope ratio analysis can be easily determined using two gaseous reference samples that differ greatly in deuterium content. ?? 1988.

  16. Method for isotope separation by photodeflection

    International Nuclear Information System (INIS)

    Bernhardt, A.F.

    1977-01-01

    In the method of separating isotopes wherein a desired isotope species is selectively deflected out of a beam of mixed isotopes by irradiating the beam with a directed beam of light of narrowly defined frequency which is selectively absorbed by the desired species, the improvement comprising irradiating the deflected beam with light from other light sources whose frequencies are selected to cause the depopulation of any metastable excited states

  17. Isotope hydrology: A historical overview of achievements

    International Nuclear Information System (INIS)

    1997-01-01

    The IAEA's efforts in the water sector cover all aspects of the three main categories of isotope methodologies, such as the use of radioactive isotopes as tracers for site-specific investigations related to water movement; the use of sealed radioactive sources for in-situ measurement of hydrological field parameters; and the use of naturally occurring isotopic species for the assessment and study of water occurrence, genesis and flow pathways/dynamics at regional-scale hydrological systems

  18. Isotope separation by ionic cyclotron resonance

    International Nuclear Information System (INIS)

    Compant La Fontaine, A.; Gil, C.; Louvet, P.

    1986-10-01

    The principle of the process of isotopic separation by ionic cyclotron resonance is explained succinctly. The theoretical calculation of the isotopic effect is given as functions of the electric and magnetic fields in the frame of single particle approximation and of plasma collective theory. Then, the main parts of the demonstration device which is in operation at the CEA, are described here: the supraconducting magnetic field, the used diagnostics, the principle of the source and the collecting apparatus. Some experimental results are given for chromium. The application of the process to ponderal separation of metal isotopes, as chromium, nickel and molybdenum is discussed in view of production of medical, structural and irradiation isotopes

  19. Treatment and storage of hydrogen isotopes

    International Nuclear Information System (INIS)

    Jung, H. S.; Lee, H. S.; An, D. H.; Kim, K. R.; Lee, S. H.; Choi, H. J.; Back, S. W.; Kang, H. S.; Eom, K. Y.; Lee, M. S.

    2000-01-01

    Storage of gaseous hydrogen isotopes in a cylinder is a well-established technology. However, Immobilization in the solid form is preferred for long-term storage of radioactive isotope gas because of the concern for leakage of the gas. The experimental thermodynamic p-c-T data show that Ti and U soak up hydrogen isotope gas at a temperature of a few hundred .deg. C and modest pressures. It was found that more hydrogen is dissolved in the metal than deuterium at constant pressure. Thus, the lighter isotope tends to be enriched in the solid phase

  20. Copper isotope fractionation by desert shrubs

    International Nuclear Information System (INIS)

    Navarrete, Jesica U.; Viveros, Marian; Ellzey, Joanne T.; Borrok, David M.

    2011-01-01

    Copper has two naturally occurring stable isotopes of masses 63 and 65 which can undergo mass dependent fractionation during various biotic and abiotic chemical reactions. These interactions and their resulting Cu isotope fractionations can be used to determine the mechanisms involved in the cycling of Cu in natural systems. In this study, Cu isotope changes were investigated at the organismal level in the metal-accumulating desert plant, Prosopis pubescens. Initial results suggest that the lighter Cu isotope was preferentially incorporated into the leaves of the plant, which may suggest that Cu was actively transported via intracellular proteins. The roots and stems show a smaller degree of Cu isotope fractionation and the direction and magnitude of the fractionations was dependent upon the levels of Cu exposure. Based on this and previous work with bacteria and yeast, a trend is emerging that suggests the lighter Cu isotope is preferentially incorporated into biological components, while the heavier Cu isotope tends to become enriched in aqueous solutions. In bacteria, plants and animals, intracellular Cu concentrations are strictly regulated via dozens of enzymes that can bind, transport, and store Cu. Many of these enzymes reduce Cu(II) to Cu(I). These initial results seem to fit into a broader picture of Cu isotope cycling in natural systems where oxidation/reduction reactions are fundamental in controlling the distributions of Cu isotopes.

  1. Stable Isotope Group 1984 progress report

    International Nuclear Information System (INIS)

    Lyon, G.L.

    1985-04-01

    The work of the group in 1984 is described and includes studies in isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation. Geothermal studies have decreased compared to other years, but major data summaries were made for Wairakei and Ngawha. The hydrology of Whakarewarewa and Rotorua is being elucidated using water isotopes. Models of the subsurface flows at Kawerau and Ngawha are being made to relate fluid to mineral isotope compositions. A study of the δ 13 C and δ 34 S compositions of New Zealand oils has been started. Groups of oils of related origin are being defined, and compositions will be compared with those of potential source rocks. A method was developed for isotope analysis of sulphur in rocks. The isotopic composition of water is being used to identify and characterise groundwater aquifers in the Wairarapa and at Poverty Bay. Stable carbon isotopes have been used to identify food sources for invertebrates, and to show biochemical pathways in lactation by cows. The geochronology group is involved in major studies in Antarctica, using U-Pb, Rb-Sr and K-Ar methods. Rocks from North Victoria Land, Marie Byrd Land and the USARP mountains are being compared with possible correlatives in New Zealand and Argentina. Strontium isotope data is being applied to the origin of magmas in several regions of New Zealand. The K-Ar data is being stored on computer files. Fission track measurements are being applied to unravel uplift histories in Westland and Taranaki

  2. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T. R.; McInteer, B. B.; Montoya, J. G.

    1988-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S vs. 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF 4 . 8 refs., 2 tabs

  3. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T.R.; McInteer, B.B.; Montoya, J.G.

    1989-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of theses isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separations of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S and 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produces separated isotopes with an effect similar to that found for sulfur in SF 4 . (author). 8 refs.; 2 tabs

  4. On models in the geochemistry of isotopes

    International Nuclear Information System (INIS)

    Wetzel, K.

    1978-01-01

    Models are playing an increasing role in the deepening of our understanding of the laws of occurrence of stable and radioactive isotopes in nature. The properties of concrete global and regional models of the geochemistry of isotopes are derived from a general model characterizing the cycling of chemical elements and their isotopes in nature. The importance of global models as well as the relationships between global and regional models are considered. The introduction of a parameter describing the velocity of both mass and isotope transfer, taking into consideration the global resources, renders possible the linkage of global models with regional ones. (author)

  5. Lead isotope analyses of standard rock samples

    International Nuclear Information System (INIS)

    Koide, Yoshiyuki; Nakamura, Eizo

    1990-01-01

    New results on lead isotope compositions of standard rock samples and their analytical procedures are reported. Bromide form anion exchange chromatography technique was adopted for the chemical separation lead from rock samples. The lead contamination during whole analytical procedure was low enough to determine lead isotope composition of common natural rocks. Silica-gel activator method was applied for emission of lead ions in the mass spectrometer. Using the data reduction of 'unfractionated ratios', we obtained good reproducibility, precision and accuracy on lead isotope compositions of NBS SRM. Here we present new reliable lead isotope compositions of GSJ standard rock samples and USGS standard rock, BCR-1. (author)

  6. Equilibrium deuterium isotope effect of surprising magnitude

    International Nuclear Information System (INIS)

    Goldstein, M.J.; Pressman, E.J.

    1981-01-01

    Seemingly large deuterium isotope effects are reported for the preference of deuterium for the α-chloro site to the bridgehead or to the vinyl site in samples of anti-7-chlorobicyclo[4.3.2]undecatetraene-d 1 . Studies of molecular models did not provide a basis for these large equilibrium deuterium isotope effects. The possibility is proposed that these isotope effects only appear to be large for want of comparison with isotope effects measured for molecules that might provide even greater contrasts in local force fields

  7. Development of stable isotope manufacturing in Russia

    International Nuclear Information System (INIS)

    Pokidychev, A.; Pokidycheva, M.

    1999-01-01

    For the past 25 years, Russia has relied heavily on the electromagnetic separation process for the production of middle and heavy mass stable isotopes. The separation of most light isotopes had been centered in Georgia which, after the collapse of the USSR, left Russia without this capability. In the mid-1970s, development of centrifuge technology for the separation of stable isotopes was begun. Alternative techniques such as laser separation, physical-chemical methods, and ion cyclotron resonance have also been investigated. Economic considerations have played a major role in the development and current status of the stable isotope enrichment capabilities of Russia

  8. Trees, astronomy, ruins and isotopes

    International Nuclear Information System (INIS)

    Thwaites, R.N.

    1985-01-01

    The history of dendrochronology is traced from the discovery of the method to prove astronomic sun-spot cycles to its use in archaeology for dating purposes. The principles and problems of both dendrochronology and radiocarbon 14 C dating are described and the subsequent relationship of the two sciences in aiding the calibration of absolute dating methods using carbon isotopes is explained. The development of graphic calibration, which introduces a seemingly erratic curve, is discussed as regards its validity for accurate dating up to 50 000 years B.P. Whilst dendrochronology continues in other spheres as a science in its own right, the polemics surrounding valid radiocarbon calibration remain

  9. Isotopic diagnosis of peripheral thrombosis

    International Nuclear Information System (INIS)

    Cornu, Pierre; Scalet, Michel

    1975-01-01

    Radio-isotope diagnosis of peripheral venous thrombosis, using tracer doses of iodine-labelled fibrinogen, provides an important contribution to the solution of the worrying problem of pulmonary embolism due to latent phlebitis. This elegant and precise technique permits early diagnosis of venous thrombosis of the lower limbs at a subclinical stage. It has permitted determination of the frequency, both after surgery and after myocardial infarction, and above all, it provides an objective criterion for assessment of the efficacy of prophylactic measures proposed [fr

  10. Isotope hydrology in Latin America

    International Nuclear Information System (INIS)

    Payne, B.R.

    1976-01-01

    There are a broad range of nuclear techniques applicable to a variety of hydrological problems and these techniques are becoming recognized as an additional and, in some cases, indispensable tool available to the hydrologist in his quest to meet the increasing demands for water by agriculture, industry and community water supply. In Latin America we find examples of almost all the nuclear hydrological techniques. This article endeavours to give a summary account of the status of isotope hydrology in the region and the types of problems to which these techniques have been applied

  11. Reproducibility of isotope ratio measurements

    International Nuclear Information System (INIS)

    Elmore, D.

    1981-01-01

    The use of an accelerator as part of a mass spectrometer has improved the sensitivity for measuring low levels of long-lived radionuclides by several orders of magnitude. However, the complexity of a large tandem accelerator and beam transport system has made it difficult to match the precision of low energy mass spectrometry. Although uncertainties for accelerator measured isotope ratios as low as 1% have been obtained under favorable conditions, most errors quoted in the literature for natural samples are in the 5 to 20% range. These errors are dominated by statistics and generally the reproducibility is unknown since the samples are only measured once

  12. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  13. Nuclear data for unstable isotopes

    International Nuclear Information System (INIS)

    Sorlin, O.

    1992-01-01

    Nuclear Physics and Astrophysics are both entrusted with the task of understanding nucleosynthesis and energy production in the stars. At high temperatures and densities present in explosive scenarii such as the early universe, cataclysmic binary stars (nova or accretion stars), and supernovae, the nucleosynthesis proceeds throughout unstable nuclei. In order to produce and to study the most exotic isotopes that are not accessible from stable beam - stable (or radioactive) target experiments, it is necessary to develop facilities that utilize Radioactive Nuclear Beams (RNB). The existing methods for producing unstable nuclei will be described in paragraph 2. A review of the major explosive stellar processes will be made through some selected examples using RNB

  14. Self diffusion in isotopic fluid

    International Nuclear Information System (INIS)

    Tankeshwar, K.

    1991-01-01

    Expressions for the second and fourth frequency sum rules of the velocity auto-correlation function have been obtained for an isotopic fluid. These expressions and Mori memory function formalism have been used to study the influence of the particle mass and mole fraction on the self diffusion coefficient. Our results confirm the weak mass dependence of the self diffusion. The influence of the mole fraction of the light particles on the self diffusion constant has been found to increase for the larger particle mass. (author). 17 refs, 1 fig., 2 tabs

  15. Exploring the isotopic niche: isotopic variance, physiological incorporation, and the temporal dynamics of foraging

    Directory of Open Access Journals (Sweden)

    Justin Douglas Yeakel

    2016-01-01

    Full Text Available Consumer foraging behaviors are dynamic, changing in response to prey availability, seasonality, competition, and even the consumer's physiological state. The isotopic composition of a consumer is a product of these factors as well as the isotopic `landscape' of its prey, i.e. the isotopic mixing space. Stable isotope mixing models are used to back-calculate the most likely proportional contribution of a set of prey to a consumer's diet based on their respective isotopic distributions, however they are disconnected from ecological process. Here we build a mechanistic framework that links the ecological and physiological processes of an individual consumer to the isotopic distribution that describes its diet, and ultimately to the isotopic composition of its own tissues, defined as its `isotopic niche’. By coupling these processes, we systematically investigate under what conditions the isotopic niche of a consumer changes as a function of both the geometric properties of its mixing space and foraging strategies that may be static or dynamic over time. Results of our derivations reveal general insight into the conditions impacting isotopic niche width as a function of consumer specialization on prey, as well as the consumer's ability to transition between diets over time. We show analytically that moderate specialization on isotopically unique prey can serve to maximize a consumer's isotopic niche width, while temporally dynamic diets will tend to result in peak isotopic variance during dietary transitions. We demonstrate the relevance of our theoretical findings by examining a marine system composed of nine invertebrate species commonly consumed by sea otters. In general, our analytical framework highlights the complex interplay of mixing space geometry and consumer dietary behavior in driving expansion and contraction of the isotopic niche. Because this approach is established on ecological mechanism, it is well-suited for enhancing the

  16. Radiogenic isotope geochemistry of sedimentary and aquatic systems

    International Nuclear Information System (INIS)

    Stille, P.; Shields, G.

    1997-01-01

    The following topics are discussed: Basic principles of isotopic geochemistry; weathering; isotopic geochemistry of river water; isotopic geochemistry in the environment; isotopic composition of seawater past and present (Sr, Nd, Pb, Os, Ce); isotope geochemistry of detrital and authigenic clay minerals in marine sediemnts (Rb-Sr, K-Ar, O); the Sm-N isotope system in detrital and authigenic argillaceous sediments. (SR), provided they are of exceptional interest and focused on a single topic. (orig./SR)

  17. Radiogenic isotope geochemistry of sedimentary and aquatic systems

    Energy Technology Data Exchange (ETDEWEB)

    Stille, P.; Shields, G. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Centre de Sedimentologie et Geochimie de la Surface

    1997-12-31

    The following topics are discussed: Basic principles of isotopic geochemistry; weathering; isotopic geochemistry of river water; isotopic geochemistry in the environment; isotopic composition of seawater past and present (Sr, Nd, Pb, Os, Ce); isotope geochemistry of detrital and authigenic clay minerals in marine sediemnts (Rb-Sr, K-Ar, O); the Sm-N isotope system in detrital and authigenic argillaceous sediments. (SR), provided they are of exceptional interest and focused on a single topic. (orig./SR)

  18. Isotope separations using chromatographic methods

    International Nuclear Information System (INIS)

    Leseticky, L.

    1985-01-01

    A survey is given of chromatographic separations of compounds only differing in isotope composition. Isotope effects on physical properties which allow chromatographic separation (vapour tension, adsorption heat, partition coefficient) are very small, with the exception of the simplest molecules. Therefore, separation factors only assume the value of several per cent. From this ensues the necessity of using columns which are specially and very carefully prepared and have a separation efficiency of the order of 10 4 theoretical plates. Briefly discussed is liquid chromatography on ion exchangers which with a varied degree of success was used for separating simple inorganic compounds or ions. Ion exchange chromatography of amino acids labelled with tritium, and chromatography of tritium labelled steroids also provided only a certain degree of separation. A detailed analysis is presented of gas chromatography separation of various deuterium and tritium labelled low-molecular compounds, to which a number of studies has been devoted in the literature. Very promising is the method of complexation gas chromatography based on the reversible formation of a complex of the ligand (the compound being separated) and the compound of the (transition) metal as the steady-state phase. (author)

  19. Isotope separation by rotating plasmas

    International Nuclear Information System (INIS)

    Nicoli, C.

    1982-02-01

    A steady-state model of a fully ionized plasma column in a concentric cylindrical electrodes structures is proposed to study the plasma separation properties of its singly ionized ionic species, composed of two isotopes of the element. In this model (a one-fluid model) rotation is imparted to the plasma column through the J (vector) x B (vector) interaction. Radial pressure balance is mainly between the radial component of the J (vector) x B (vector) force and the pressure gradient plus centrifugal force and the azimutal component of the J (vector) x B (vector) force is balanced purely by viscous force. A pressure tensor 31 describes the viscoys effect and the heat balance provides an equation for temperature. A uranium gas with is two main isotopes (U 235 and U 238 ) was used for the ionic component of the plasma. The computing code to solve the resulting, system of equations in tems of density, temperature, and velocity as functions of the radial independent variable was set up to yield solutions satisfying null velocity conditions on both boundaries (inner and outer electrodes). (M.A.F.) [pt

  20. Isotopic scintigraphy in kidney grafting

    International Nuclear Information System (INIS)

    Renfro, Richard.

    1976-01-01

    Isotopic explorations of kidney transplants were performed on sixty-six patients. Three scintigraphic techniques were used: labelled ferrous ascorbate scintigraphy, sequential 99m technetium DTPA scintigraphy and the 131 I hippuran nephrogram. The aim of this study is to analyse the results obtained under different pathological circumstances affecting the transplant, to discuss the advantages of the techniques and to propose a working procedure. The most reliable and accurate technique is the 131 I hippuran nephrogram combined with sequential 99mTc DTPA, by which renal vascularisation may be judged labelled ferrous ascorbate on the other hand is too insensitive. Although the information supplied is mostly contained in the scintigraphic images, the nephrographic curves and the blood radioactivity decay time and rad V/rad R ratio measurements are very helpful in the early diagnosis and differential diagnosis of complications affecting the transplant. The proper use of isotopic scintigraphy in kidney grafting should provide optimum conditions for better survival of the transplant at minimum risk to the patient [fr

  1. Isotopic variations in primitive meteorites

    International Nuclear Information System (INIS)

    Clayton, R.N.; Chicago Univ., IL; Chicago Univ., IL

    1981-01-01

    The presence of large internal 16 O variability in ordinary chondrites greatly extends the range of meteorite types in which this phenomenon has been observed. These results may lead to identification of major gas and dust reservoirs in the cloud from which the Solar System formed. The demonstration that live 107 Pd was present in the differentiated parent bodies of some iron meteorites supports the million year time scale between a major nucleosynthetic event and Solar System formation, as implied by the presence of live 26 Al in carbonaceous chondrites. However, the variability of radiogenic 26 Mg abundances in these meteorites makes it clear that the data cannot be interpreted simply in terms of time variations. Models of nucleosynthesis for elements from calcium to the iron peak should be aided by the new observations of abundances of titanium isotopes. Progress has been made in establishing the carrier phases of isotopically anomalous xenon and krypton. The apparent location of anomalous xenon and 14 N-rich nitrogen in identical carriers supports the notion that nucleosynthetic anomalies in nitrogen are also present in Allende. (author)

  2. Isotope scanning for tumor localization

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1961-09-15

    At the request of the Government of the United Arab Republic, the Agency provided the services of an expert for the establishment in the UAR of a tumor localization program using photoscanning techniques and appropriate radioactive tracers. Photoscanning is a recently developed technique whereby the differences in isotope concentrations are enhanced on the record, and this facilitates the interpretation of the record. A variety of brain tumors were located, using a suitable radioactive tracer (Hg-203 - labelled Neohydrin) obtained from the USA. In some other investigations, processes in the kidney were scanned. Further, radioactive gold was used to demonstrate the normal and pathological spleen and liver and these tests showed various types of space occupying lesions resulting from malignancy and the parasitic infections endemic to the area. While the localization of brain tumors by scanning techniques is extremely useful, it does not always establish the precise extent of the tumor which should be known at the time of surgery. Dr. Bender, therefore, thought it advisable to instruct personnel in the use of what is known as an in-vivo needle scintillation probe - a technique for the investigation of the isotope concentration in a particular tissue during operation. The necessary instrument was obtained for this purpose and demonstrations were given; one patient was examined in this way at the time of surgery at the University of Alexandria Hospital.

  3. Ion detectors for isotopic measurements

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, A.

    1978-12-15

    Detector development over the past two decades has been such that this is now the least likely part of the mass spectrometry equipment to give rise to the sort of measurement errors to cause concern. It is now possible to choose from a number of different types of device which can provide more or less 100% efficiency in ion beam detection under all conceivable experimental conditions required for isotopic analysis, from measurement of large samples using the traditional Faraday cage to measurement of exceedingly small ion currents by ion counting techniques. There are even methods of distinguishing one type of ionic species from another in the detector, thus improving the accuracy when unwanted isobaric species might otherwise grossly distort the measurement. Notable contributions to detector development for nuclear measurements have been made by Dietz at the Knolls Atomic Power Laboratory, by Barnett at Oak Ridge and by Daly at Atomic Weapons Research Establishment (AWRE), Aldermaston. This paper describes the detection methods which are currently in use at AWRE for isotopic analysis of solid samples for routine applications as well as non-routine applications. Other methods are merely mentioned as a stimulus for discussion.

  4. Kinetic equation of heterogeneous catalytic isotope exchange

    Energy Technology Data Exchange (ETDEWEB)

    Trokhimets, A I [AN Belorusskoj SSR, Minsk. Inst. Fiziko-Organicheskoj Khimii

    1979-12-01

    A kinetic equation is derived for the bimolecular isotope exchange reaction between AXsub(n)sup(*) and BXsub(m)sup(o), all atoms of element X in each molecule being equivalent. The equation can be generalized for homogeneous and heterogeneous catalytic isotope exchange.

  5. Status and prospects of isotope separation industry

    International Nuclear Information System (INIS)

    Safutin, V.D.; Verbin, Yu.V.; Tolstoj, V.V.

    2000-01-01

    The stages of the separation industry in the USSR and Russia are demonstrated. The current status of the separation industry and state of the equipment of the isotope separation plants are noted. The developed program for the modernization of the uranium isotope separation involves the production of perspective gas centrifuges, the improvements in the works of gas centrifuge plants and construction materials [ru

  6. Using isotopes for global warming observation

    International Nuclear Information System (INIS)

    Namata, K.

    2002-01-01

    This paper, based on a literature review, discusses the main aspects of using isotopic techniques to obtain information about global warming. The rapid increase concentration of carbon dioxide (CO 2 ) and methane (CH 4 ) in the atmosphere will result in global warming by the greenhouse effect, and the isotopic techniques constitute an efficient tool to explain this complex environmental phenomenon. (author)

  7. Environmental isotopes investigation in groundwater of Challaghatta ...

    African Journals Online (AJOL)

    Administrator

    Radiogenic isotopes (3H and 14C) and stable isotope (18O) together with TDS, EC and salinity of water were used to ..... Tritium (3H). Relative dating of groundwater has been carried ... that falls to Earth has small amounts of tritium. During the.

  8. The isotopic dipole moment of HDO

    Energy Technology Data Exchange (ETDEWEB)

    Assafrao, Denise; Mohallem, Jose R [Laboratorio de Atomos e Moleculas Especiais, Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, 30123-970, Belo Horizonte, MG (Brazil)

    2007-03-14

    An adiabatic variational approximation is used to study the monodeuterated water molecule, HDO, accounting for the isotopic effect. The isotopic dipole moment, pointing from D to H, is then calculated for the first time, yielding (1.5 {+-} 0.1) x 10{sup -3} Debye, being helpful in the interpretation of experiments. (fast track communication)

  9. Atomic lithium vapor laser isotope separation

    CERN Document Server

    Olivares, I E

    2002-01-01

    An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the sup 6 LiD sub 2 and the sup 7 LiD sub 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

  10. Atomic lithium vapor laser isotope separation

    International Nuclear Information System (INIS)

    Olivares, I.E.; Rojas, C.

    2002-01-01

    An atomic vapor laser isotope separation in lithium was performed using tunable diode lasers. The method permits also the separation of the isotopes between the 6 LiD 2 and the 7 LiD 1 lines using a self-made mass separator which includes a magnetic sector and an ion beam designed for lithium. (Author)

  11. Applications of stable isotopes in clinical pharmacology

    NARCIS (Netherlands)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the

  12. Isotope and chemical tracers in groundwater hydrology

    International Nuclear Information System (INIS)

    Kendall, C.; Stewart, M.K.; Morgenstern, U.; Trompetter, V.

    1999-01-01

    The course sessions cover: session 1, Fundamentals of stable and radioactive isotopes; session 2, Stable oxygen and hydrogen isotopes in hydrology: background, examples, sampling strategy; session 3, Catchment studies using oxygen and hydrogen isotopes: background - the hydrologic water balance, evapotranspiration - the lion's share, runoff generation - new water/old water fractions, groundwater recharge - the crumbs; session 4, Isotopes in catchment hydrology: survey of applications, future developments; session 5, Applications of tritium in hydrology: background and measurement, interpretation, examples; session 6, Case studies using mixing models: Hutt Valley groundwater system, an extended mixing model for simulating tracer transport in the unsaturated zone; session 7, Groundwater dating using CFC concentrations: background, sampling and measurement, use and applications; session 8, Groundwater dating with carbon-14: background, sampling and measurement, use and applications; session 9, NZ case studies: Tauranga warm springs, North Canterbury Plains groundwater; session 10, Stable carbon and nitrogen isotopes: background and examples, biological applications of C-N-S isotopes; session 11, New developments in isotope hydrology: gas isotopes, compound specific applications, age dating of sediments etc; session 12, NZ case studies: North Canterbury Plains groundwater (continued), Waimea Plains groundwater. (author). refs., figs

  13. Absolute isotopic abundances of Ti in meteorites

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.; Wasserburg, G.J.

    1985-01-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46 Ti/ 48 Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. We provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components. The absolute Ti and Ca isotopic compositions still support the correlation of 50 Ti and 48 Ca effects in the FUN inclusions and imply contributions from neutron-rich equilibrium or quasi-equilibrium nucleosynthesis. The present identification of endemic effects at 46 Ti, for the absolute composition, implies a shortfall of an explosive-oxygen component or reflects significant isotope fractionation. Additional nucleosynthetic components are required by 47 Ti and 49 Ti effects. Components are also defined in which 48 Ti is enhanced. Results are given and discussed. (author)

  14. Isotope separation by selective photodissociation of glyoxal

    International Nuclear Information System (INIS)

    Marling, J.B.

    1976-01-01

    Dissociation products, mainly formaldehyde and carbon monoxide, enriched in a desired isotope of carbon, oxygen, or hydrogen are obtained by the selective photodissociation of glyoxal wherein glyoxal is subjected to electromagnetic radiation in a predetermined wavelength such that photon absorption excites and induces dissociation of only those molecules of glyoxal containing the desired isotope

  15. Method and apparatus for separating uranium isotopes

    International Nuclear Information System (INIS)

    Bernstein, E.R.

    1977-01-01

    A uranium compound in the solid phase (uranium borohydride four) is subjected to radiation of a first predetermined frequency that excites the uranium-235 isotope-bearing molecules but not the uranium-238 isotope-bearing molecules. The compound is simultaneously subjected to radiation of a second predetermined frequency which causes the excited uranium-235 isotope-bearing molecules to chemically decompose but which does not affect the uranium-238 isotope-bearing molecules. Sufficient heat is then applied to the irradiated compound in the solid phase to vaporize the non-decomposed uranium-238 isotope-bearing molecules but not the decomposed uranium-235 isotope-bearing molecules, thereby physically separating the uranium-235 isotope-bearing molecules from the uranium-238 isotope-bearing molecules. The uranium compound sample in the solid phase is deposited or grown in an elongated tube supported within a dewar vessel having a clear optical path tail section surrounded by a coolant. Two sources of radiation are focused on the uranium compound sample. A heating element is attached to the elongated tube to vaporize the irradiated compound

  16. Application of isotopes in traditional Chinese medicine

    International Nuclear Information System (INIS)

    Ye Ling; Liu Ning; Yang Yuanyou; Mo Shangwu

    2006-01-01

    Modernization of traditional Chinese medicine necessitates many new or advanced methods. Among these methods, isotopes are considered to be a convenient, fast and feasible method. The recent advance of isotope's application to traditional Chinese medicine is reviewed. In addition, their present status, problems and prospect are discussed. (authors)

  17. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  18. isotopic characteristics of aquifers in sinai

    International Nuclear Information System (INIS)

    Al-Gamal, S.A.

    2004-01-01

    the environmental isotopes data (expressed as δ 2 d and δ 18 O) of different aquifers in sinai were treated using correlation and regression techniques. whereas, rain water isotopic data were treated using empirical orthogonal functions (EOF) techniques. environmental isotopes for different aquifers expressed in terms of O-18 and H-2, were taken to represent the isotopic characteristics. regression equations using the highly correlated variables of δ 2 d and δ 18 O were constructed for each aquifer. the latitudinal variations (of rainwater in sinai and selected climatic stations east mediterranean ) versus rainwater isotopic compositions were analyzed using the normalized variables. it was found that the latitudinal variations of the rainwater isotopic compositions ( δ 2 D, δ 18 O), vapor pressure, and surface temperature occurred in parallel and decreased with latitude. in the east mediterranean, empirical linear relationship between altitude and δ 2 D has indicted that the rate of change of δ 2 D with height is comparable with the dry lapse rate in the atmosphere.The obtained regression equations of environmental isotopes data have impacted on different slopes and different constants expressing the non-homogeneity in the isotopic composition of rainwater recharging the aquifers of sinai , due to the presence of different air masses

  19. Gas isotope separation method using plasma sheet

    International Nuclear Information System (INIS)

    Takayama, K.; Takagi, K.; Fukvi, R.

    1988-03-01

    A high frequency electric field is applied to a plasma sheet with a frequency equal to the cyclotronic frequency of the ions to be separated. Because of resonance the cyclotronic radius of the isotope has increased and the electric charge is eliminated by collision with a separator and the isotope is separated in neutral particles [fr

  20. Safeguards implications of laser isotope separation

    International Nuclear Information System (INIS)

    Moriarty, T.F.; Taylor, K.

    1993-10-01

    The purpose of this report is to describe and emphasise the safeguards and relevant features of atomic vapour laser isotope separation (AVLIS) and molecular laser isotope separation (MLIS), and to consider the issues that must be addressed before a safeguards approach at a commercial AVLIS or MLIS facility can be implemented. (Author)